<s>
Python	B-Language
is	O
a	O
high-level	B-Language
,	O
general-purpose	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
Its	O
design	O
philosophy	O
emphasizes	O
code	O
readability	O
with	O
the	O
use	O
of	O
significant	O
indentation	O
via	O
the	O
off-side	B-Language
rule	I-Language
.	O
</s>
<s>
Python	B-Language
is	O
dynamically	O
typed	O
and	O
garbage-collected	B-General_Concept
.	O
</s>
<s>
It	O
supports	O
multiple	O
programming	O
paradigms	O
,	O
including	O
structured	B-Language
(	O
particularly	O
procedural	B-Application
)	O
,	O
object-oriented	B-Language
and	O
functional	B-Language
programming	I-Language
.	O
</s>
<s>
It	O
is	O
often	O
described	O
as	O
a	O
"	O
batteries	O
included	O
"	O
language	O
due	O
to	O
its	O
comprehensive	O
standard	B-Library
library	I-Library
.	O
</s>
<s>
Guido	O
van	O
Rossum	O
began	O
working	O
on	O
Python	B-Language
in	O
the	O
late	O
1980s	O
as	O
a	O
successor	O
to	O
the	O
ABC	B-Language
programming	I-Language
language	I-Language
and	O
first	O
released	O
it	O
in	O
1991	O
as	O
Python0.9.0	O
.	O
</s>
<s>
Python3.0	O
,	O
released	O
in	O
2008	O
,	O
was	O
a	O
major	O
revision	O
not	O
completely	O
backward-compatible	B-General_Concept
with	O
earlier	O
versions	O
.	O
</s>
<s>
Python	B-Language
consistently	O
ranks	O
as	O
one	O
of	O
the	O
most	O
popular	O
programming	O
languages	O
.	O
</s>
<s>
Python	B-Language
was	O
conceived	O
in	O
the	O
late	O
1980s	O
by	O
Guido	O
van	O
Rossum	O
at	O
Centrum	O
Wiskunde	O
&	O
Informatica	O
(	O
CWI	O
)	O
in	O
the	O
Netherlands	O
as	O
a	O
successor	O
to	O
the	O
ABC	B-Language
programming	I-Language
language	I-Language
,	O
which	O
was	O
inspired	O
by	O
SETL	B-Language
,	O
capable	O
of	O
exception	B-General_Concept
handling	I-General_Concept
and	O
interfacing	O
with	O
the	O
Amoeba	B-Operating_System
operating	O
system	O
.	O
</s>
<s>
Van	O
Rossum	O
shouldered	O
sole	O
responsibility	O
for	O
the	O
project	O
,	O
as	O
the	O
lead	O
developer	O
,	O
until	O
12	O
July	O
2018	O
,	O
when	O
he	O
announced	O
his	O
"	O
permanent	O
vacation	O
"	O
from	O
his	O
responsibilities	O
as	O
Python	B-Language
's	O
"	O
benevolent	O
dictator	O
for	O
life	O
"	O
,	O
a	O
title	O
the	O
Python	B-Language
community	O
bestowed	O
upon	O
him	O
to	O
reflect	O
his	O
long-term	O
commitment	O
as	O
the	O
project	O
's	O
chief	O
decision-maker	O
.	O
</s>
<s>
In	O
January2019	O
,	O
active	O
Python	B-Language
core	O
developers	O
elected	O
a	O
five-member	O
Steering	O
Council	O
to	O
lead	O
the	O
project	O
.	O
</s>
<s>
Python2.0	O
was	O
released	O
on	O
16	O
October	O
2000	O
,	O
with	O
many	O
major	O
new	O
features	O
such	O
as	O
list	B-Language
comprehensions	I-Language
,	O
cycle-detecting	B-Algorithm
garbage	B-General_Concept
collection	I-General_Concept
,	O
reference	B-General_Concept
counting	I-General_Concept
,	O
and	O
Unicode	O
support	O
.	O
</s>
<s>
Python3.0	O
,	O
released	O
on	O
3	O
December	O
2008	O
,	O
with	O
many	O
of	O
its	O
major	O
features	O
backported	O
to	O
Python2.6.x	O
and	O
2.7.x	O
.	O
</s>
<s>
Releases	O
of	O
Python3	B-Language
include	O
the	O
2to3	O
utility	O
,	O
which	O
automates	O
the	O
translation	O
of	O
Python2	O
code	O
to	O
Python3	B-Language
.	O
</s>
<s>
Python2.7	O
'	O
s	O
end-of-life	O
was	O
initially	O
set	O
for	O
2015	O
,	O
then	O
postponed	O
to	O
2020	O
out	O
of	O
concern	O
that	O
a	O
large	O
body	O
of	O
existing	O
code	O
could	O
not	O
easily	O
be	O
forward-ported	O
to	O
Python3	B-Language
.	O
</s>
<s>
In	O
2021	O
,	O
Python3.9.2	O
and	O
3.8.8	O
were	O
expedited	O
as	O
all	O
versions	O
of	O
Python	B-Language
(	O
including	O
2.7	O
)	O
had	O
security	O
issues	O
leading	O
to	O
possible	O
remote	O
code	O
execution	O
and	O
web	B-General_Concept
cache	I-General_Concept
poisoning	I-General_Concept
.	O
</s>
<s>
In	O
2022	O
,	O
Python3.10.4	O
and	O
3.9.12	O
were	O
expedited	O
and	O
3.8.13	O
,	O
and	O
3.7.13	O
,	O
because	O
of	O
many	O
security	O
issues	O
.	O
</s>
<s>
When	O
Python3.9.13	O
was	O
released	O
in	O
May	O
2022	O
,	O
it	O
was	O
announced	O
that	O
the	O
3.9	O
series	O
(	O
joining	O
the	O
older	O
series	O
3.8	O
and	O
3.7	O
)	O
would	O
only	O
receive	O
security	O
fixes	O
in	O
the	O
future	O
.	O
</s>
<s>
Python3.11	O
is	O
the	O
stable	O
release	O
.	O
</s>
<s>
Notable	O
changes	O
from	O
3.10	O
include	O
increased	O
program	O
execution	O
speed	O
and	O
improved	O
error	B-General_Concept
reporting	I-General_Concept
.	O
</s>
<s>
Python	B-Language
is	O
a	O
multi-paradigm	O
programming	O
language	O
.	O
</s>
<s>
Object-oriented	B-Language
programming	I-Language
and	O
structured	B-Language
programming	I-Language
are	O
fully	O
supported	O
,	O
and	O
many	O
of	O
their	O
features	O
support	O
functional	B-Language
programming	I-Language
and	O
aspect-oriented	B-Architecture
programming	I-Architecture
(	O
including	O
metaprogramming	B-Application
and	O
metaobjects	O
)	O
.	O
</s>
<s>
Many	O
other	O
paradigms	O
are	O
supported	O
via	O
extensions	O
,	O
including	O
design	B-Application
by	I-Application
contract	I-Application
and	O
logic	B-Language
programming	I-Language
.	O
</s>
<s>
Python	B-Language
uses	O
dynamic	O
typing	O
and	O
a	O
combination	O
of	O
reference	B-General_Concept
counting	I-General_Concept
and	O
a	O
cycle-detecting	B-Algorithm
garbage	B-General_Concept
collector	I-General_Concept
for	O
memory	B-General_Concept
management	I-General_Concept
.	O
</s>
<s>
It	O
uses	O
dynamic	B-Application
name	I-Application
resolution	I-Application
(	O
late	O
binding	B-Application
)	O
,	O
which	O
binds	O
method	B-Language
and	O
variable	O
names	O
during	O
program	O
execution	O
.	O
</s>
<s>
Its	O
design	O
offers	O
some	O
support	O
for	O
functional	B-Language
programming	I-Language
in	O
the	O
Lisp	B-Language
tradition	O
.	O
</s>
<s>
It	O
has	O
functions	O
;	O
list	B-Language
comprehensions	I-Language
,	O
dictionaries	B-Application
,	O
sets	O
,	O
and	O
generator	B-Language
expressions	I-Language
.	O
</s>
<s>
The	O
standard	B-Library
library	I-Library
has	O
two	O
modules	B-Architecture
(	O
and	O
)	O
that	O
implement	O
functional	B-Language
tools	O
borrowed	O
from	O
Haskell	B-Language
and	O
Standard	B-Language
ML	I-Language
.	O
</s>
<s>
Its	O
core	O
philosophy	O
is	O
summarized	O
in	O
the	O
document	O
The	O
Zen	O
of	O
Python	B-Language
(	O
PEP	O
20	O
)	O
,	O
which	O
includes	O
aphorisms	O
such	O
as	O
:	O
</s>
<s>
Rather	O
than	O
building	O
all	O
of	O
its	O
functionality	O
into	O
its	O
core	O
,	O
Python	B-Language
was	O
designed	O
to	O
be	O
highly	O
extensible	B-Architecture
via	O
modules	B-Architecture
.	O
</s>
<s>
This	O
compact	O
modularity	B-Architecture
has	O
made	O
it	O
particularly	O
popular	O
as	O
a	O
means	O
of	O
adding	O
programmable	O
interfaces	O
to	O
existing	O
applications	O
.	O
</s>
<s>
Van	O
Rossum	O
's	O
vision	O
of	O
a	O
small	O
core	O
language	O
with	O
a	O
large	O
standard	B-Library
library	I-Library
and	O
easily	O
extensible	B-Architecture
interpreter	O
stemmed	O
from	O
his	O
frustrations	O
with	O
ABC	B-Language
,	O
which	O
espoused	O
the	O
opposite	O
approach	O
.	O
</s>
<s>
Python	B-Language
strives	O
for	O
a	O
simpler	O
,	O
less-cluttered	O
syntax	O
and	O
grammar	O
while	O
giving	O
developers	O
a	O
choice	O
in	O
their	O
coding	O
methodology	O
.	O
</s>
<s>
In	O
contrast	O
to	O
Perl	B-Language
's	O
"	O
there	B-Architecture
is	I-Architecture
more	I-Architecture
than	I-Architecture
one	I-Architecture
way	I-Architecture
to	I-Architecture
do	I-Architecture
it	I-Architecture
"	O
motto	O
,	O
Python	B-Language
embraces	O
a	O
"	O
there	O
should	O
be	O
one	O
—	O
and	O
preferably	O
only	O
one	O
—	O
obvious	O
way	O
to	O
do	O
it	O
"	O
philosophy	O
.	O
</s>
<s>
Alex	O
Martelli	O
,	O
a	O
Fellow	O
at	O
the	O
Python	B-Application
Software	I-Application
Foundation	I-Application
and	O
Python	B-Language
book	O
author	O
,	O
wrote	O
:	O
"	O
To	O
describe	O
something	O
as	O
'	O
clever	O
 '	O
is	O
not	O
considered	O
a	O
compliment	O
in	O
the	O
Python	B-Language
culture.	O
"	O
</s>
<s>
Python	B-Language
's	O
developers	O
strive	O
to	O
avoid	O
premature	O
optimization	O
and	O
reject	O
patches	O
to	O
non-critical	O
parts	O
of	O
the	O
CPython	B-Language
reference	O
implementation	O
that	O
would	O
offer	O
marginal	O
increases	O
in	O
speed	O
at	O
the	O
cost	O
of	O
clarity	O
.	O
</s>
<s>
When	O
speed	O
is	O
important	O
,	O
a	O
Python	B-Language
programmer	O
can	O
move	O
time-critical	O
functions	O
to	O
extension	O
modules	B-Architecture
written	O
in	O
languages	O
such	O
as	O
C	B-Language
;	O
or	O
use	O
PyPy	B-Language
,	O
a	O
just-in-time	O
compiler	B-Language
.	O
</s>
<s>
Cython	B-Application
is	O
also	O
available	O
,	O
which	O
translates	O
a	O
Python	B-Language
script	I-Language
into	O
C	B-Language
and	O
makes	O
direct	O
C-level	O
API	O
calls	O
into	O
the	O
Python	B-Language
interpreter	O
.	O
</s>
<s>
Python	B-Language
's	O
developers	O
aim	O
for	O
it	O
to	O
be	O
fun	O
to	O
use	O
.	O
</s>
<s>
This	O
is	O
reflected	O
in	O
its	O
name	O
—	O
a	O
tribute	O
to	O
the	O
British	O
comedy	O
group	O
Monty	O
Python	B-Language
—	O
and	O
in	O
occasionally	O
playful	O
approaches	O
to	O
tutorials	O
and	O
reference	O
materials	O
,	O
such	O
as	O
the	O
use	O
of	O
the	O
terms	O
"	O
spam	O
"	O
and	O
"	O
eggs	O
"	O
(	O
a	O
reference	O
to	O
a	O
Monty	O
Python	B-Language
sketch	O
)	O
in	O
examples	O
,	O
instead	O
of	O
the	O
often-used	O
"	O
foo	O
"	O
and	O
"	O
bar	O
"	O
.	O
</s>
<s>
A	O
common	O
neologism	O
in	O
the	O
Python	B-Language
community	O
is	O
pythonic	O
,	O
which	O
has	O
a	O
wide	O
range	O
of	O
meanings	O
related	O
to	O
program	O
style	O
.	O
</s>
<s>
"	O
Pythonic	O
"	O
code	O
may	O
use	O
Python	B-Language
idioms	O
well	O
,	O
be	O
natural	O
or	O
show	O
fluency	O
in	O
the	O
language	O
,	O
or	O
conform	O
with	O
Python	B-Language
's	O
minimalist	O
philosophy	O
and	O
emphasis	O
on	O
readability	O
.	O
</s>
<s>
Python	B-Language
is	O
meant	O
to	O
be	O
an	O
easily	O
readable	O
language	O
.	O
</s>
<s>
It	O
has	O
fewer	O
syntactic	O
exceptions	O
and	O
special	O
cases	O
than	O
C	B-Language
or	O
Pascal	B-Application
.	O
</s>
<s>
Python	B-Language
uses	O
whitespace	O
indentation	O
,	O
rather	O
than	O
curly	O
brackets	O
or	O
keywords	O
,	O
to	O
delimit	O
blocks	O
.	O
</s>
<s>
This	O
feature	O
is	O
sometimes	O
termed	O
the	O
off-side	B-Language
rule	I-Language
.	O
</s>
<s>
Python	B-Language
's	O
statements	O
include	O
:	O
</s>
<s>
In	O
Python	B-Language
,	O
a	O
variable	O
name	O
is	O
a	O
generic	O
reference	O
holder	O
without	O
a	O
fixed	O
data	O
type	O
;	O
however	O
,	O
it	O
always	O
refers	O
to	O
some	O
object	O
with	O
a	O
type	O
.	O
</s>
<s>
Python	B-Language
does	O
not	O
support	O
tail	B-Language
call	I-Language
optimization	I-Language
or	O
first-class	O
continuations	O
,	O
and	O
,	O
according	O
to	O
Van	O
Rossum	O
,	O
it	O
never	O
will	O
.	O
</s>
<s>
However	O
,	O
better	O
support	O
for	O
coroutine-like	O
functionality	O
is	O
provided	O
by	O
extending	O
Python	B-Language
's	O
generators	O
.	O
</s>
<s>
Python	B-Language
's	O
expressions	O
include	O
:	O
</s>
<s>
There	O
are	O
two	O
types	O
of	O
divisions	O
in	O
Python	B-Language
:	O
floor	O
division	O
(	O
or	O
integer	O
division	O
)	O
//	O
and	O
floating-point/division	O
.	O
</s>
<s>
Python	B-Language
uses	O
the	O
**	O
operator	O
for	O
exponentiation	O
.	O
</s>
<s>
Python	B-Language
uses	O
the	O
+	O
operator	O
for	O
string	O
concatenation	O
.	O
</s>
<s>
Python	B-Language
uses	O
the	O
*	O
operator	O
for	O
duplicating	O
a	O
string	O
a	O
specified	O
number	O
of	O
times	O
.	O
</s>
<s>
It	O
is	O
intended	O
to	O
be	O
used	O
by	O
libraries	O
such	O
as	O
NumPy	B-Application
for	O
matrix	O
multiplication	O
.	O
</s>
<s>
The	O
syntax	O
:=	O
,	O
called	O
the	O
"	O
walrus	O
operator	O
"	O
,	O
was	O
introduced	O
in	O
Python	B-Language
3.8	O
.	O
</s>
<s>
In	O
Python	B-Language
,	O
==	O
compares	O
by	O
value	O
.	O
</s>
<s>
Python	B-Language
's	O
is	O
operator	O
may	O
be	O
used	O
to	O
compare	O
object	O
identities	O
(	O
comparison	O
by	O
reference	O
)	O
,	O
and	O
comparisons	O
may	O
be	O
chained	O
—	O
for	O
example	O
,	O
.	O
</s>
<s>
Python	B-Language
uses	O
and	O
,	O
or	O
,	O
and	O
not	O
as	O
boolean	O
operators	O
.	O
</s>
<s>
Python	B-Language
has	O
a	O
type	O
of	O
expression	O
called	O
a	O
list	B-Language
comprehension	I-Language
,	O
as	O
well	O
as	O
a	O
more	O
general	O
expression	O
called	O
a	O
generator	B-Language
expression	I-Language
.	O
</s>
<s>
Anonymous	B-General_Concept
functions	I-General_Concept
are	O
implemented	O
using	O
lambda	B-General_Concept
expressions	I-General_Concept
;	O
however	O
,	O
there	O
may	O
be	O
only	O
one	O
expression	O
in	O
each	O
body	O
.	O
</s>
<s>
Conditional	B-Language
expressions	O
are	O
written	O
as	O
(	O
different	O
in	O
order	O
of	O
operands	O
from	O
the	O
c	B-Language
?	O
</s>
<s>
Python	B-Language
makes	O
a	O
distinction	O
between	O
lists	O
and	O
tuples	B-Application
.	O
</s>
<s>
Lists	O
are	O
written	O
as	O
,	O
are	O
mutable	B-Application
,	O
and	O
cannot	O
be	O
used	O
as	O
the	O
keys	O
of	O
dictionaries	B-Application
(	O
dictionary	B-Application
keys	O
must	O
be	O
immutable	B-Application
in	O
Python	B-Language
)	O
.	O
</s>
<s>
Tuples	B-Application
,	O
written	O
as	O
,	O
are	O
immutable	B-Application
and	O
thus	O
can	O
be	O
used	O
as	O
keys	O
of	O
dictionaries	B-Application
,	O
provided	O
all	O
of	O
the	O
tuple	B-Application
's	O
elements	O
are	O
immutable	B-Application
.	O
</s>
<s>
The	O
+	O
operator	O
can	O
be	O
used	O
to	O
concatenate	O
two	O
tuples	B-Application
,	O
which	O
does	O
not	O
directly	O
modify	O
their	O
contents	O
,	O
but	O
produces	O
a	O
new	O
tuple	B-Application
containing	O
the	O
elements	O
of	O
both	O
.	O
</s>
<s>
Thus	O
,	O
given	O
the	O
variable	O
t	O
initially	O
equal	O
to	O
,	O
executing	O
first	O
evaluates	O
,	O
which	O
yields	O
,	O
which	O
is	O
then	O
assigned	O
back	O
to	O
t	O
—	O
thereby	O
effectively	O
"	O
modifying	O
the	O
contents	O
"	O
of	O
t	O
while	O
conforming	O
to	O
the	O
immutable	B-Application
nature	O
of	O
tuple	B-Application
objects	O
.	O
</s>
<s>
Parentheses	O
are	O
optional	O
for	O
tuples	B-Application
in	O
unambiguous	O
contexts	O
.	O
</s>
<s>
Python	B-Language
features	O
sequence	O
unpacking	O
where	O
multiple	O
expressions	O
,	O
each	O
evaluating	O
to	O
anything	O
that	O
can	O
be	O
assigned	O
(	O
to	O
a	O
variable	O
,	O
writable	O
property	O
,	O
etc	O
.	O
)	O
</s>
<s>
are	O
associated	O
in	O
an	O
identical	O
manner	O
to	O
that	O
forming	O
tuple	B-Application
literals	O
—	O
and	O
,	O
as	O
a	O
whole	O
,	O
are	O
put	O
on	O
the	O
left-hand	O
side	O
of	O
the	O
equal	O
sign	O
in	O
an	O
assignment	O
statement	O
.	O
</s>
<s>
Python	B-Language
has	O
a	O
"	O
string	O
format	O
"	O
operator	O
%	O
that	O
functions	O
analogously	O
to	O
printf	B-Language
format	I-Language
strings	I-Language
in	O
C	B-Language
—	O
e.g.	O
</s>
<s>
In	O
Python2.6	O
+	O
and	O
3+	O
,	O
this	O
was	O
supplemented	O
by	O
the	O
format( )	O
method	B-Language
of	O
the	O
str	O
class	O
,	O
e.g.	O
</s>
<s>
Python3.6	O
added	O
"	O
f-strings	O
"	O
:	O
.	O
</s>
<s>
Strings	O
in	O
Python	B-Language
can	O
be	O
concatenated	O
by	O
"	O
adding	O
"	O
them	O
(	O
with	O
the	O
same	O
operator	O
as	O
for	O
adding	O
integers	O
and	O
floats	B-Algorithm
)	O
,	O
e.g.	O
</s>
<s>
If	B-Language
strings	O
contain	O
numbers	O
,	O
they	O
are	O
added	O
as	O
strings	O
rather	O
than	O
integers	O
,	O
e.g.	O
</s>
<s>
Python	B-Language
has	O
various	O
string	B-Language
literals	I-Language
:	O
</s>
<s>
Delimited	O
by	O
single	O
or	O
double	O
quote	O
marks	O
;	O
unlike	O
in	O
Unix	B-Application
shells	I-Application
,	O
Perl	B-Language
,	O
and	O
Perl-influenced	O
languages	O
,	O
single	O
and	O
double	O
quote	O
marks	O
work	O
the	O
same	O
.	O
</s>
<s>
Both	O
use	O
the	O
backslash	O
(	O
\	O
)	O
as	O
an	O
escape	B-Algorithm
character	I-Algorithm
.	O
</s>
<s>
String	O
interpolation	O
became	O
available	O
in	O
Python3.6	O
as	O
"	O
formatted	O
string	B-Language
literals	I-Language
"	O
.	O
</s>
<s>
Triple-quoted	O
(	O
beginning	O
and	O
ending	O
with	O
three	O
single	O
or	O
double	O
quote	O
marks	O
)	O
,	O
which	O
may	O
span	O
multiple	O
lines	O
and	O
function	O
like	O
here	O
documents	O
in	O
shells	O
,	O
Perl	B-Language
,	O
and	O
Ruby	B-Language
.	O
</s>
<s>
Raw	O
string	O
varieties	O
,	O
denoted	O
by	O
prefixing	O
the	O
string	B-Language
literal	I-Language
with	O
r	O
.	O
Escape	O
sequences	O
are	O
not	O
interpreted	O
;	O
hence	O
raw	O
strings	O
are	O
useful	O
where	O
literal	O
backslashes	O
are	O
common	O
,	O
such	O
as	O
regular	B-Language
expressions	I-Language
and	O
Windows-style	O
paths	O
.	O
</s>
<s>
(	O
Compare	O
"	O
@	O
-quoting	O
"	O
in	O
C#	B-Application
.	O
)	O
</s>
<s>
Python	B-Language
has	O
array	O
index	O
and	O
array	O
slicing	O
expressions	O
in	O
lists	O
,	O
denoted	O
as	O
a[key],	O
or	O
.	O
</s>
<s>
In	O
Python	B-Language
,	O
a	O
distinction	O
between	O
expressions	O
and	O
statements	O
is	O
rigidly	O
enforced	O
,	O
in	O
contrast	O
to	O
languages	O
such	O
as	O
Common	B-Language
Lisp	I-Language
,	O
Scheme	B-Language
,	O
or	O
Ruby	B-Language
.	O
</s>
<s>
Statements	O
cannot	O
be	O
a	O
part	O
of	O
an	O
expression	O
—	O
so	O
list	O
and	O
other	O
comprehensions	O
or	O
lambda	B-General_Concept
expressions	I-General_Concept
,	O
all	O
being	O
expressions	O
,	O
cannot	O
contain	O
statements	O
.	O
</s>
<s>
A	O
particular	O
case	O
is	O
that	O
an	O
assignment	O
statement	O
such	O
as	O
cannot	O
form	O
part	O
of	O
the	O
conditional	B-Language
expression	O
of	O
a	O
conditional	B-Language
statement	O
.	O
</s>
<s>
This	O
has	O
the	O
advantage	O
of	O
avoiding	O
a	O
classic	O
C	B-Language
error	O
of	O
mistaking	O
an	O
assignment	O
operator	O
=	O
for	O
an	O
equality	O
operator	O
==	O
in	O
conditions	O
:	O
}	O
is	O
syntactically	O
valid	O
(	O
but	O
probably	O
unintended	O
)	O
C	B-Language
code	O
,	O
but	O
causes	O
a	O
syntax	O
error	O
in	O
Python	B-Language
.	O
</s>
<s>
Methods	B-Language
on	O
objects	O
are	O
functions	O
attached	O
to	O
the	O
object	O
's	O
class	O
;	O
the	O
syntax	O
is	O
,	O
for	O
normal	O
methods	B-Language
and	O
functions	O
,	O
syntactic	O
sugar	B-Language
for	O
.	O
</s>
<s>
Python	B-Language
methods	B-Language
have	O
an	O
explicit	O
self	B-Application
parameter	O
to	O
access	O
instance	B-Application
data	I-Application
,	O
in	O
contrast	O
to	O
the	O
implicit	O
self	B-Application
(	O
or	O
this	O
)	O
in	O
some	O
other	O
object-oriented	B-Language
programming	I-Language
languages	I-Language
(	O
e.g.	O
,	O
C++	B-Language
,	O
Java	B-Language
,	O
Objective-C	B-Language
,	O
Ruby	B-Language
)	O
.	O
</s>
<s>
Python	B-Language
also	O
provides	O
methods	B-Language
,	O
often	O
called	O
dunder	O
methods	B-Language
(	O
due	O
to	O
their	O
names	O
beginning	O
and	O
ending	O
with	O
double-underscores	O
)	O
,	O
to	O
allow	O
user-defined	O
classes	O
to	O
modify	O
how	O
they	O
are	O
handled	O
by	O
native	O
operations	O
including	O
length	O
,	O
comparison	O
,	O
in	O
arithmetic	O
operations	O
and	O
type	O
conversion	O
.	O
</s>
<s>
Python	B-Language
uses	O
duck	B-Application
typing	I-Application
and	O
has	O
typed	O
objects	O
but	O
untyped	O
variable	O
names	O
.	O
</s>
<s>
Type	O
constraints	O
are	O
not	O
checked	O
at	O
compile	B-Application
time	I-Application
;	O
rather	O
,	O
operations	O
on	O
an	O
object	O
may	O
fail	O
,	O
signifying	O
that	O
it	O
is	O
not	O
of	O
a	O
suitable	O
type	O
.	O
</s>
<s>
Despite	O
being	O
dynamically	O
typed	O
,	O
Python	B-Language
is	O
strongly	O
typed	O
,	O
forbidding	O
operations	O
that	O
are	O
not	O
well-defined	O
(	O
for	O
example	O
,	O
adding	O
a	O
number	O
to	O
a	O
string	O
)	O
rather	O
than	O
silently	O
attempting	O
to	O
make	O
sense	O
of	O
them	O
.	O
</s>
<s>
Python	B-Language
allows	O
programmers	O
to	O
define	O
their	O
own	O
types	O
using	O
classes	O
,	O
most	O
often	O
used	O
for	O
object-oriented	B-Language
programming	I-Language
.	O
</s>
<s>
New	O
instances	O
of	O
classes	O
are	O
constructed	O
by	O
calling	O
the	O
class	O
(	O
for	O
example	O
,	O
or	O
)	O
,	O
and	O
the	O
classes	O
are	O
instances	O
of	O
the	O
metaclass	B-Language
type	O
(	O
itself	O
an	O
instance	O
of	O
itself	O
)	O
,	O
allowing	O
metaprogramming	B-Application
and	O
reflection	B-Language
.	O
</s>
<s>
Before	O
version3.0	O
,	O
Python	B-Language
had	O
two	O
kinds	O
of	O
classes	O
(	O
both	O
using	O
the	O
same	O
syntax	O
)	O
:	O
old-style	O
and	O
new-style	O
,	O
current	O
Python	B-Language
versions	O
only	O
support	O
the	O
semantics	O
new	O
style	O
.	O
</s>
<s>
Python	B-Language
supports	O
gradual	O
typing	O
.	O
</s>
<s>
Python	B-Language
's	O
syntax	O
allows	O
specifying	O
static	O
types	O
,	O
but	O
they	O
are	O
not	O
checked	O
in	O
the	O
default	O
implementation	O
,	O
CPython	B-Language
.	O
</s>
<s>
An	O
experimental	O
optional	O
static	O
type-checker	O
,	O
mypy	O
,	O
supports	O
compile-time	B-Application
type	O
checking	O
.	O
</s>
<s>
+	O
Summary	O
of	O
Python	B-Language
3	O
's	O
built-in	O
types	O
Type	O
Mutability	B-Application
Description	O
Syntax	O
examples	O
bool	O
immutable	B-Application
Boolean	O
value	O
bytearray	O
mutable	B-Application
Sequence	O
of	O
bytes	B-Application
bytes	B-Application
immutable	B-Application
Sequence	O
of	O
bytes	B-Application
complex	O
immutable	B-Application
Complex	O
number	O
with	O
real	O
and	O
imaginary	O
parts	O
dict	O
mutable	B-Application
Associative	B-Application
array	I-Application
(	O
or	O
dictionary	B-Application
)	O
of	O
key	O
and	O
value	O
pairs	O
;	O
can	O
contain	O
mixed	O
types	O
(	O
keys	O
and	O
values	O
)	O
,	O
keys	O
must	O
be	O
a	O
hashable	O
type	O
}}	O
types.EllipsisType	O
immutable	B-Application
An	O
ellipsis	O
placeholder	B-Language
to	O
be	O
used	O
as	O
an	O
index	O
in	O
NumPy	B-Application
arrays	O
float	B-Algorithm
immutable	B-Application
Double-precision	O
floating-point	B-Algorithm
number	I-Algorithm
.	O
</s>
<s>
frozenset	O
immutable	B-Application
Unordered	O
set	O
,	O
contains	O
no	O
duplicates	O
;	O
can	O
contain	O
mixed	O
types	O
,	O
if	B-Language
hashable	O
int	O
immutable	B-Application
Integer	O
of	O
unlimited	O
magnitude	O
list	O
mutable	B-Application
List	O
,	O
can	O
contain	O
mixed	O
types	O
types.NoneType	O
immutable	B-Application
An	O
object	O
representing	O
the	O
absence	O
of	O
a	O
value	O
,	O
often	O
called	O
null	O
in	O
other	O
languages	O
types.NotImplementedType	O
immutable	B-Application
A	O
placeholder	B-Language
that	O
can	O
be	O
returned	O
from	O
overloaded	O
operators	O
to	O
indicate	O
unsupported	O
operand	O
types	O
.	O
</s>
<s>
Python	B-Language
has	O
the	O
usual	O
symbols	O
for	O
arithmetic	O
operators	O
( +	O
,	O
-	O
,	O
*	O
,	O
/	O
)	O
,	O
the	O
floor	O
division	O
operator	O
//	O
and	O
the	O
modulo	O
operation	O
%	O
(	O
where	O
the	O
remainder	O
can	O
be	O
negative	O
,	O
e.g.	O
</s>
<s>
The	O
division	O
between	O
integers	O
produces	O
floating-point	B-Algorithm
results	O
.	O
</s>
<s>
Current	O
Python	B-Language
(	O
i.e.	O
</s>
<s>
since	O
3.0	O
)	O
changed	O
/	O
to	O
always	O
be	O
floating-point	B-Algorithm
division	O
,	O
e.g.	O
</s>
<s>
Adding	O
causes	O
a	O
module	B-Architecture
used	O
in	O
Python	B-Language
2.7	O
to	O
use	O
Python3.0	O
rules	O
for	O
division	O
(	O
see	O
above	O
)	O
.	O
</s>
<s>
In	O
Python	B-Language
terms	O
,	O
/	O
is	O
true	O
division	O
(	O
or	O
simply	O
division	O
)	O
,	O
and	O
//	O
is	O
floor	O
division	O
.	O
</s>
<s>
Rounding	B-Algorithm
towards	O
negative	O
infinity	O
,	O
though	O
different	O
from	O
most	O
languages	O
,	O
adds	O
consistency	O
.	O
</s>
<s>
Python	B-Language
provides	O
a	O
round	O
function	O
for	O
rounding	B-Algorithm
a	O
float	B-Algorithm
to	O
the	O
nearest	B-Algorithm
integer	I-Algorithm
.	O
</s>
<s>
For	O
tie-breaking	O
,	O
Python3	B-Language
uses	O
round	O
to	O
even	O
:	O
round( 	O
1.5	O
)	O
and	O
round( 	O
2.5	O
)	O
both	O
produce	O
2	O
.	O
</s>
<s>
Python	B-Language
allows	O
boolean	O
expressions	O
with	O
multiple	O
equality	O
relations	O
in	O
a	O
manner	O
that	O
is	O
consistent	O
with	O
general	O
use	O
in	O
mathematics	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
expression	O
a	O
<	O
b	O
<	O
c	B-Language
tests	O
whether	O
a	B-Application
is	I-Application
less	O
than	O
b	O
and	O
b	O
is	O
less	O
than	O
c	B-Language
.	O
C-derived	O
languages	O
interpret	O
this	O
expression	O
differently	O
:	O
in	O
C	B-Language
,	O
the	O
expression	O
would	O
first	O
evaluate	O
a	O
<	O
b	O
,	O
resulting	O
in	O
0	O
or	O
1	O
,	O
and	O
that	O
result	O
would	O
then	O
be	O
compared	O
with	O
c	B-Language
.	O
</s>
<s>
Python	B-Language
uses	O
arbitrary-precision	B-Algorithm
arithmetic	I-Algorithm
for	O
all	O
integer	O
operations	O
.	O
</s>
<s>
The	O
Decimal	O
type/class	O
in	O
the	O
decimal	O
module	B-Architecture
provides	O
decimal	O
floating-point	B-Algorithm
numbers	I-Algorithm
to	O
a	O
pre-defined	O
arbitrary	B-Algorithm
precision	I-Algorithm
and	O
several	O
rounding	B-Algorithm
modes	O
.	O
</s>
<s>
The	O
Fraction	O
class	O
in	O
the	O
fractions	O
module	B-Architecture
provides	O
arbitrary	B-Algorithm
precision	I-Algorithm
for	O
rational	O
numbers	O
.	O
</s>
<s>
Due	O
to	O
Python	B-Language
's	O
extensive	O
mathematics	O
library	O
,	O
and	O
the	O
third-party	O
library	O
NumPy	B-Application
that	O
further	O
extends	O
the	O
native	O
capabilities	O
,	O
it	O
is	O
frequently	O
used	O
as	O
a	O
scientific	O
scripting	B-Language
language	I-Language
to	O
aid	O
in	O
problems	O
such	O
as	O
numerical	O
data	O
processing	O
and	O
manipulation	O
.	O
</s>
<s>
Python	B-Language
's	O
large	O
standard	B-Library
library	I-Library
provides	O
tools	O
suited	O
to	O
many	O
tasks	O
and	O
is	O
commonly	O
cited	O
as	O
one	O
of	O
its	O
greatest	O
strengths	O
.	O
</s>
<s>
For	O
Internet-facing	O
applications	O
,	O
many	O
standard	O
formats	O
and	O
protocols	O
such	O
as	O
MIME	B-Protocol
and	O
HTTP	B-Protocol
are	O
supported	O
.	O
</s>
<s>
It	O
includes	O
modules	B-Architecture
for	O
creating	O
graphical	B-Application
user	I-Application
interfaces	I-Application
,	O
connecting	O
to	O
relational	B-Application
databases	I-Application
,	O
generating	B-Algorithm
pseudorandom	I-Algorithm
numbers	I-Algorithm
,	O
arithmetic	O
with	O
arbitrary-precision	B-Algorithm
decimals	O
,	O
manipulating	O
regular	B-Language
expressions	I-Language
,	O
and	O
unit	O
testing	O
.	O
</s>
<s>
Some	O
parts	O
of	O
the	O
standard	B-Library
library	I-Library
are	O
covered	O
by	O
specifications	O
—	O
for	O
example	O
,	O
the	O
Web	B-Language
Server	I-Language
Gateway	I-Language
Interface	I-Language
(	O
WSGI	B-Language
)	O
implementation	O
wsgiref	O
follows	O
PEP	O
333	O
—	O
but	O
most	O
are	O
specified	O
by	O
their	O
code	O
,	O
internal	O
documentation	O
,	O
and	O
test	O
suites	O
.	O
</s>
<s>
However	O
,	O
because	O
most	O
of	O
the	O
standard	B-Library
library	I-Library
is	O
cross-platform	O
Python	B-Language
code	I-Language
,	O
only	O
a	O
few	O
modules	B-Architecture
need	O
altering	O
or	O
rewriting	O
for	O
variant	O
implementations	O
.	O
</s>
<s>
the	O
Python	B-Language
Package	I-Language
Index	I-Language
(	O
PyPI	B-Language
)	O
,	O
the	O
official	O
repository	O
for	O
third-party	O
Python	B-Language
software	O
,	O
contains	O
over	O
415,000	O
packages	O
with	O
a	O
wide	O
range	O
of	O
functionality	O
,	O
including	O
:	O
</s>
<s>
Most	O
Python	B-Language
implementations	O
(	O
including	O
CPython	B-Language
)	O
include	O
a	O
read	B-Application
–	I-Application
eval	I-Application
–	I-Application
print	I-Application
loop	I-Application
(	O
REPL	B-Application
)	O
,	O
permitting	O
them	O
to	O
function	O
as	O
a	O
command	O
line	O
interpreter	O
for	O
which	O
users	O
enter	O
statements	O
sequentially	O
and	O
receive	O
results	O
immediately	O
.	O
</s>
<s>
Python	B-Language
also	O
comes	O
with	O
an	O
Integrated	B-Application
development	I-Application
environment	I-Application
(	O
IDE	O
)	O
called	O
IDLE	B-Application
,	O
which	O
is	O
more	O
beginner-oriented	O
.	O
</s>
<s>
Other	O
shells	O
,	O
including	O
IDLE	B-Application
and	O
IPython	B-Application
,	O
add	O
further	O
abilities	O
such	O
as	O
improved	O
auto-completion	O
,	O
session	O
state	O
retention	O
,	O
and	O
syntax	O
highlighting	O
.	O
</s>
<s>
As	O
well	O
as	O
standard	O
desktop	O
integrated	B-Application
development	I-Application
environments	I-Application
,	O
there	O
are	O
Web	O
browser-based	B-Application
IDEs	O
,	O
including	O
SageMath	B-Application
,	O
for	O
developing	O
science	O
-	O
and	O
math-related	O
programs	O
;	O
PythonAnywhere	B-Language
,	O
a	O
browser-based	B-Application
IDE	O
and	O
hosting	O
environment	O
;	O
and	O
Canopy	O
IDE	O
,	O
a	O
commercial	O
IDE	O
emphasizing	O
scientific	O
computing	O
.	O
</s>
<s>
CPython	B-Language
is	O
the	O
reference	O
implementation	O
of	O
Python	B-Language
.	O
</s>
<s>
It	O
is	O
written	O
in	O
C	B-Language
,	O
meeting	O
the	O
C89	O
standard	O
(	O
Python	B-Language
3.11	O
uses	O
C11	O
)	O
with	O
several	O
select	O
C99	B-Language
features	O
.	O
</s>
<s>
CPython	B-Language
includes	O
its	O
own	O
C	B-Language
extensions	O
,	O
but	O
third-party	O
extensions	O
are	O
not	O
limited	O
to	O
older	O
C	B-Language
versions	O
—	O
e.g.	O
</s>
<s>
they	O
can	O
be	O
implemented	O
with	O
C11	O
or	O
C++	B-Language
.	O
)	O
</s>
<s>
It	O
compiles	B-Language
Python	B-Language
programs	I-Language
into	O
an	O
intermediate	O
bytecode	O
which	O
is	O
then	O
executed	O
by	O
its	O
virtual	B-Architecture
machine	I-Architecture
.	O
</s>
<s>
CPython	B-Language
is	O
distributed	O
with	O
a	O
large	O
standard	B-Library
library	I-Library
written	O
in	O
a	O
mixture	O
of	O
C	B-Language
and	O
native	O
Python	B-Language
,	O
and	O
is	O
available	O
for	O
many	O
platforms	O
,	O
including	O
Windows	B-Application
(	O
starting	O
with	O
Python3.9	O
,	O
the	O
Python	B-Language
installer	O
deliberately	O
fails	O
to	O
install	O
on	O
Windows	B-Device
7	I-Device
and	O
8	O
;	O
Windows	B-Application
XP	I-Application
was	O
supported	O
until	O
Python3.5	O
)	O
and	O
most	O
modern	O
Unix-like	B-Operating_System
systems	I-Operating_System
,	O
including	O
macOS	B-Application
(	O
and	O
Apple	B-Device
M1	I-Device
Macs	O
,	O
since	O
Python3.9.1	O
,	O
with	O
experimental	O
installer	O
)	O
and	O
unofficial	O
support	O
for	O
e.g.	O
</s>
<s>
VMS	B-Operating_System
.	O
</s>
<s>
(	O
During	O
Python1	O
and	O
2	O
development	O
,	O
even	O
OS/2	B-Application
and	O
Solaris	B-Application
were	O
supported	O
,	O
but	O
support	O
has	O
since	O
been	O
dropped	O
for	O
many	O
platforms	O
.	O
)	O
</s>
<s>
PyPy	B-Language
is	O
a	O
fast	O
,	O
compliant	O
interpreter	O
of	O
Python2.7	O
and	O
3.8	O
.	O
</s>
<s>
Its	O
just-in-time	O
compiler	B-Language
often	O
brings	O
a	O
significant	O
speed	O
improvement	O
over	O
CPython	B-Language
but	O
some	O
libraries	O
written	O
in	O
C	B-Language
cannot	O
be	O
used	O
with	O
it	O
.	O
</s>
<s>
Stackless	B-Operating_System
Python	I-Operating_System
is	O
a	O
significant	O
fork	O
of	O
CPython	B-Language
that	O
implements	O
microthreads	B-Operating_System
;	O
it	O
does	O
not	O
use	O
the	O
call	B-General_Concept
stack	I-General_Concept
in	O
the	O
same	O
way	O
,	O
thus	O
allowing	O
massively	O
concurrent	O
programs	O
.	O
</s>
<s>
PyPy	B-Language
also	O
has	O
a	O
stackless	B-Operating_System
version	O
.	O
</s>
<s>
MicroPython	B-Language
and	O
CircuitPython	B-Device
are	O
Python3	B-Language
variants	O
optimized	O
for	O
microcontrollers	B-Architecture
,	O
including	O
Lego	B-Application
Mindstorms	I-Application
EV3	I-Application
.	O
</s>
<s>
Pyston	B-Language
is	O
a	O
variant	O
of	O
the	O
Python	B-Language
runtime	O
that	O
uses	O
just-in-time	O
compilation	B-Language
to	O
speed	O
up	O
the	O
execution	O
of	O
Python	B-Language
programs	I-Language
.	O
</s>
<s>
Cinder	O
is	O
a	O
performance-oriented	O
fork	O
of	O
CPython	B-Language
3.8	O
that	O
contains	O
a	O
number	O
of	O
optimizations	O
including	O
bytecode	O
inline	O
caching	O
,	O
eager	O
evaluation	O
of	O
coroutines	B-Architecture
,	O
a	O
method-at-a-time	O
JIT	O
,	O
and	O
an	O
experimental	O
bytecode	O
compiler	B-Language
.	O
</s>
<s>
Other	O
just-in-time	O
Python	B-Language
compilers	B-Language
have	O
been	O
developed	O
,	O
but	O
are	O
now	O
unsupported	O
:	O
</s>
<s>
Google	B-Application
began	O
a	O
project	O
named	O
Unladen	O
Swallow	O
in	O
2009	O
,	O
with	O
the	O
aim	O
of	O
speeding	O
up	O
the	O
Python	B-Language
interpreter	O
fivefold	O
by	O
using	O
the	O
LLVM	B-Application
,	O
and	O
of	O
improving	O
its	O
multithreading	O
ability	O
to	O
scale	O
to	O
thousands	O
of	O
cores	O
,	O
while	O
ordinary	O
implementations	O
suffer	O
from	O
the	O
global	B-Operating_System
interpreter	I-Operating_System
lock	I-Operating_System
.	O
</s>
<s>
Psyco	B-Language
is	O
a	O
discontinued	O
just-in-time	O
specializing	B-Algorithm
compiler	I-Algorithm
that	O
integrates	O
with	O
CPython	B-Language
and	O
transforms	O
bytecode	O
to	O
machine	O
code	O
at	O
runtime	O
.	O
</s>
<s>
The	O
emitted	O
code	O
is	O
specialized	O
for	O
certain	O
data	O
types	O
and	O
is	O
faster	O
than	O
the	O
standard	O
Python	B-Language
code	I-Language
.	O
</s>
<s>
Psyco	B-Language
does	O
not	O
support	O
Python2.7	O
or	O
later	O
.	O
</s>
<s>
PyS60	B-Application
was	O
a	O
Python2	O
interpreter	O
for	O
Series	B-Language
60	I-Language
mobile	O
phones	O
released	O
by	O
Nokia	O
in	O
2005	O
.	O
</s>
<s>
It	O
implemented	O
many	O
of	O
the	O
modules	B-Architecture
from	O
the	O
standard	B-Library
library	I-Library
and	O
some	O
additional	O
modules	B-Architecture
for	O
integrating	O
with	O
the	O
Symbian	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
.	O
</s>
<s>
The	O
Nokia	B-Application
N900	I-Application
also	O
supports	O
Python	B-Language
with	O
GTK	B-Application
widget	O
libraries	O
,	O
enabling	O
programs	O
to	O
be	O
written	O
and	O
run	O
on	O
the	O
target	O
device	O
.	O
</s>
<s>
There	O
are	O
several	O
compilers	B-Language
to	O
high-level	B-Language
object	O
languages	O
,	O
with	O
either	O
unrestricted	O
Python	B-Language
,	O
a	O
restricted	O
subset	O
of	O
Python	B-Language
,	O
or	O
a	O
language	O
similar	O
to	O
Python	B-Language
as	O
the	O
source	O
language	O
:	O
</s>
<s>
Brython	O
,	O
Transcrypt	O
and	O
Pyjs	B-Language
(	O
latest	O
release	O
in	O
2012	O
)	O
compile	B-Language
Python	B-Language
to	O
JavaScript	B-Language
.	O
</s>
<s>
Cython	B-Application
compiles	B-Language
(	O
a	O
superset	O
of	O
)	O
Python	B-Language
to	O
C	B-Language
(	O
while	O
the	O
resulting	O
code	O
is	O
also	O
usable	O
with	O
Python	B-Language
and	O
also	O
e.g.	O
</s>
<s>
C++	B-Language
)	O
.	O
</s>
<s>
Nuitka	B-Language
compiles	B-Language
Python	B-Language
into	O
C	B-Language
.	O
</s>
<s>
Numba	B-Language
uses	O
LLVM	B-Application
to	O
compile	B-Language
a	O
subset	O
of	O
Python	B-Language
to	O
machine	O
code	O
.	O
</s>
<s>
Pythran	O
compiles	B-Language
a	O
subset	O
of	O
Python3	B-Language
to	O
C++	B-Language
(	O
C++11	B-Language
)	O
.	O
</s>
<s>
RPython	B-Language
can	O
be	O
compiled	B-Language
to	O
C	B-Language
,	O
and	O
is	O
used	O
to	O
build	O
the	O
PyPy	B-Language
interpreter	O
of	O
Python	B-Language
.	O
</s>
<s>
The	O
Python	B-Language
→	O
11l	O
→	O
C++	B-Language
transpiler	B-Language
compiles	B-Language
a	O
subset	O
of	O
Python3	B-Language
to	O
C++	B-Language
(	O
C++17	B-Language
)	O
.	O
</s>
<s>
MyHDL	B-Language
is	O
a	O
Python-based	O
hardware	O
description	O
language	O
(	O
HDL	O
)	O
,	O
that	O
converts	O
MyHDL	B-Language
code	O
to	O
Verilog	B-Language
or	O
VHDL	B-Language
code	O
.	O
</s>
<s>
Older	O
projects	O
(	O
or	O
not	O
to	O
be	O
used	O
with	O
Python	B-Language
3.x	O
and	O
latest	O
syntax	O
)	O
:	O
</s>
<s>
Google	B-Application
's	I-Application
Grumpy	O
(	O
latest	O
release	O
in	O
2017	O
)	O
transpiles	B-Language
Python2	O
to	O
Go	B-Application
.	O
</s>
<s>
IronPython	B-Application
allows	O
running	O
Python2.7	O
programs	O
(	O
and	O
an	O
alpha	O
,	O
released	O
in	O
2021	O
,	O
is	O
also	O
available	O
for	O
"	O
Python3.4	O
,	O
although	O
features	O
and	O
behaviors	O
from	O
later	O
versions	O
may	O
be	O
included	O
"	O
)	O
on	O
the	O
.NET	O
Common	O
Language	O
Runtime	O
.	O
</s>
<s>
Jython	B-Language
compiles	B-Language
Python2.7	O
to	O
Java	B-Language
bytecode	O
,	O
allowing	O
the	O
use	O
of	O
the	O
Java	B-Language
libraries	O
from	O
a	O
Python	B-Language
program	I-Language
.	O
</s>
<s>
Pyrex	B-Application
(	O
latest	O
release	O
in	O
2010	O
)	O
and	O
Shed	B-Application
Skin	I-Application
(	O
latest	O
release	O
in	O
2013	O
)	O
compile	B-Language
to	O
C	B-Language
and	O
C++	B-Language
respectively	O
.	O
</s>
<s>
Performance	O
comparison	O
of	O
various	O
Python	B-Language
implementations	O
on	O
a	O
non-numerical	O
(	O
combinatorial	O
)	O
workload	O
was	O
presented	O
at	O
EuroSciPy	O
'	O
13	O
.	O
</s>
<s>
Python	B-Language
's	O
performance	O
compared	O
to	O
other	O
programming	O
languages	O
is	O
also	O
benchmarked	O
by	O
The	O
Computer	O
Language	O
Benchmarks	O
Game	O
.	O
</s>
<s>
Python	B-Language
's	O
development	O
is	O
conducted	O
largely	O
through	O
the	O
Python	B-Language
Enhancement	O
Proposal	O
(	O
PEP	O
)	O
process	O
,	O
the	O
primary	O
mechanism	O
for	O
proposing	O
major	O
new	O
features	O
,	O
collecting	O
community	O
input	O
on	O
issues	O
,	O
and	O
documenting	O
Python	B-Language
design	O
decisions	O
.	O
</s>
<s>
Python	B-Language
coding	O
style	O
is	O
covered	O
in	O
PEP8	O
.	O
</s>
<s>
Outstanding	O
PEPs	O
are	O
reviewed	O
and	O
commented	O
on	O
by	O
the	O
Python	B-Language
community	O
and	O
the	O
steering	O
council	O
.	O
</s>
<s>
Enhancement	O
of	O
the	O
language	O
corresponds	O
with	O
the	O
development	O
of	O
the	O
CPython	B-Language
reference	O
implementation	O
.	O
</s>
<s>
The	O
mailing	O
list	O
python-dev	O
is	O
the	O
primary	O
forum	O
for	O
the	O
language	O
's	O
development	O
.	O
</s>
<s>
Specific	O
issues	O
were	O
originally	O
discussed	O
in	O
the	O
Roundup	B-Application
bug	B-Application
tracker	I-Application
hosted	O
at	O
by	O
the	O
foundation	O
.	O
</s>
<s>
In	O
2022	O
,	O
all	O
issues	O
and	O
discussions	O
were	O
migrated	O
to	O
GitHub	B-Application
.	O
</s>
<s>
Development	O
originally	O
took	O
place	O
on	O
a	O
self-hosted	O
source-code	O
repository	O
running	O
Mercurial	B-Protocol
,	O
until	O
Python	B-Language
moved	O
to	O
GitHub	B-Application
in	O
January	O
2017	O
.	O
</s>
<s>
CPython	B-Language
's	O
public	O
releases	O
come	O
in	O
three	O
types	O
,	O
distinguished	O
by	O
which	O
part	O
of	O
the	O
version	O
number	O
is	O
incremented	O
:	O
</s>
<s>
Backward-incompatible	B-General_Concept
versions	O
,	O
where	O
code	O
is	O
expected	O
to	O
break	O
and	O
needs	O
to	O
be	O
manually	O
ported	O
.	O
</s>
<s>
Starting	O
with	O
Python3.9	O
,	O
these	O
releases	O
are	O
expected	O
to	O
happen	O
annually	O
.	O
</s>
<s>
Although	O
there	O
is	O
a	O
rough	O
schedule	O
for	O
each	O
release	O
,	O
they	O
are	O
often	O
delayed	O
if	B-Language
the	O
code	O
is	O
not	O
ready	O
.	O
</s>
<s>
Python	B-Language
's	O
development	O
team	O
monitors	O
the	O
state	O
of	O
the	O
code	O
by	O
running	O
the	O
large	O
unit	O
test	O
suite	O
during	O
development	O
.	O
</s>
<s>
The	O
major	O
academic	O
conference	O
on	O
Python	B-Language
is	O
PyCon	B-Language
.	O
</s>
<s>
There	O
are	O
also	O
special	O
Python	B-Language
mentoring	O
programs	O
,	O
such	O
as	O
Pyladies	O
.	O
</s>
<s>
Python3.10	O
deprecated	O
wstr	O
(	O
to	O
be	O
removed	O
in	O
Python3.12	O
;	O
meaning	O
Python	B-Language
extensions	O
need	O
to	O
be	O
modified	O
by	O
then	O
)	O
,	O
and	O
added	O
pattern	B-Language
matching	I-Language
to	O
the	O
language	O
.	O
</s>
<s>
Tools	O
that	O
can	O
generate	O
documentation	O
for	O
Python	B-Language
API	O
include	O
pydoc	B-Protocol
(	O
available	O
as	O
part	O
of	O
the	O
standard	B-Library
library	I-Library
)	O
,	O
Sphinx	B-Language
,	O
Pdoc	B-Language
and	O
its	O
forks	O
,	O
Doxygen	B-Language
and	O
Graphviz	B-Language
,	O
among	O
others	O
.	O
</s>
<s>
Python	B-Language
's	O
name	O
is	O
derived	O
from	O
the	O
British	O
comedy	O
group	O
Monty	O
Python	B-Language
,	O
whom	O
Python	B-Language
creator	O
Guido	O
van	O
Rossum	O
enjoyed	O
while	O
developing	O
the	O
language	O
.	O
</s>
<s>
Monty	O
Python	B-Language
references	O
appear	O
frequently	O
in	O
Python	B-Language
code	I-Language
and	O
culture	O
;	O
for	O
example	O
,	O
the	O
metasyntactic	O
variables	O
often	O
used	O
in	O
Python	B-Language
literature	O
are	O
spam	O
and	O
eggs	O
instead	O
of	O
the	O
traditional	O
foo	O
and	O
bar	O
.	O
</s>
<s>
The	O
official	O
Python	B-Language
documentation	O
also	O
contains	O
various	O
references	O
to	O
Monty	O
Python	B-Language
routines	O
.	O
</s>
<s>
The	O
prefix	O
Py	O
-	O
is	O
used	O
to	O
show	O
that	O
something	O
is	O
related	O
to	O
Python	B-Language
.	O
</s>
<s>
Examples	O
of	O
the	O
use	O
of	O
this	O
prefix	O
in	O
names	O
of	O
Python	B-Language
applications	O
or	O
libraries	O
include	O
Pygame	B-Operating_System
,	O
a	O
binding	B-Application
of	O
SDL	B-Operating_System
to	O
Python	B-Language
(	O
commonly	O
used	O
to	O
create	O
games	O
)	O
;	O
PyQt	B-Language
and	O
PyGTK	B-Language
,	O
which	O
bind	O
Qt	B-Language
and	O
GTK	B-Application
to	O
Python	B-Language
respectively	O
;	O
and	O
PyPy	B-Language
,	O
a	O
Python	B-Language
implementation	O
originally	O
written	O
in	O
Python	B-Language
.	O
</s>
<s>
Since	O
2003	O
,	O
Python	B-Language
has	O
consistently	O
ranked	O
in	O
the	O
top	O
ten	O
most	O
popular	O
programming	O
languages	O
in	O
the	O
TIOBE	O
Programming	O
Community	O
Index	O
where	O
it	O
was	O
the	O
most	O
popular	O
language	O
(	O
ahead	O
of	O
C	B-Language
,	O
C++	B-Language
,	O
and	O
Java	B-Language
)	O
.	O
</s>
<s>
An	O
empirical	O
study	O
found	O
that	O
scripting	B-Language
languages	I-Language
,	O
such	O
as	O
Python	B-Language
,	O
are	O
more	O
productive	O
than	O
conventional	O
languages	O
,	O
such	O
as	O
C	B-Language
and	O
Java	B-Language
,	O
for	O
programming	O
problems	O
involving	O
string	O
manipulation	O
and	O
search	O
in	O
a	O
dictionary	B-Application
,	O
and	O
determined	O
that	O
memory	O
consumption	O
was	O
often	O
"	O
better	O
than	O
Java	B-Language
and	O
not	O
much	O
worse	O
than	O
C	B-Language
or	O
C++	B-Language
"	O
.	O
</s>
<s>
Large	O
organizations	O
that	O
use	O
Python	B-Language
include	O
Wikipedia	O
,	O
Google	B-Application
,	O
Yahoo	O
!,	O
CERN	O
,	O
NASA	O
,	O
Facebook	B-Application
,	O
Amazon	B-Application
,	O
Instagram	B-Application
,	O
Spotify	B-Application
,	O
and	O
some	O
smaller	O
entities	O
like	O
ILM	O
and	O
ITA	B-Application
.	O
</s>
<s>
The	O
social	O
news	O
networking	O
site	O
Reddit	B-Application
was	O
written	O
mostly	O
in	O
Python	B-Language
.	O
</s>
<s>
Python	B-Language
can	O
serve	O
as	O
a	O
scripting	B-Language
language	I-Language
for	O
web	B-Application
applications	I-Application
,	O
e.g.	O
,	O
via	O
for	O
the	O
Apache	B-Application
webserver	I-Application
.	O
</s>
<s>
With	O
Web	B-Language
Server	I-Language
Gateway	I-Language
Interface	I-Language
,	O
a	O
standard	O
API	O
has	O
evolved	O
to	O
facilitate	O
these	O
applications	O
.	O
</s>
<s>
Web	B-Application
frameworks	I-Application
like	O
Django	B-Language
,	O
Pylons	B-Language
,	O
Pyramid	B-Language
,	O
TurboGears	B-Language
,	O
web2py	B-Application
,	O
Tornado	B-Language
,	O
Flask	B-Language
,	O
Bottle	O
,	O
and	O
Zope	B-Language
support	O
developers	O
in	O
the	O
design	O
and	O
maintenance	O
of	O
complex	O
applications	O
.	O
</s>
<s>
Pyjs	B-Language
and	O
IronPython	B-Application
can	O
be	O
used	O
to	O
develop	O
the	O
client-side	O
of	O
Ajax-based	O
applications	O
.	O
</s>
<s>
SQLAlchemy	B-Application
can	O
be	O
used	O
as	O
a	O
data	O
mapper	O
to	O
a	O
relational	B-Application
database	I-Application
.	O
</s>
<s>
Twisted	B-Language
is	O
a	O
framework	O
to	O
program	O
communications	O
between	O
computers	O
,	O
and	O
is	O
used	O
(	O
for	O
example	O
)	O
by	O
Dropbox	B-Application
.	O
</s>
<s>
Libraries	O
such	O
as	O
NumPy	B-Application
,	O
SciPy	B-Application
,	O
and	O
Matplotlib	B-Language
allow	O
the	O
effective	O
use	O
of	O
Python	B-Language
in	O
scientific	O
computing	O
,	O
with	O
specialized	O
libraries	O
such	O
as	O
Biopython	B-Library
and	O
Astropy	B-Application
providing	O
domain-specific	O
functionality	O
.	O
</s>
<s>
SageMath	B-Application
is	O
a	O
computer	B-General_Concept
algebra	I-General_Concept
system	I-General_Concept
with	O
a	O
notebook	B-Application
interface	I-Application
programmable	O
in	O
Python	B-Language
:	O
its	O
library	O
covers	O
many	O
aspects	O
of	O
mathematics	O
,	O
including	O
algebra	O
,	O
combinatorics	O
,	O
numerical	B-General_Concept
mathematics	I-General_Concept
,	O
number	O
theory	O
,	O
and	O
calculus	O
.	O
</s>
<s>
OpenCV	B-Language
has	O
Python	B-Language
bindings	O
with	O
a	O
rich	O
set	O
of	O
features	O
for	O
computer	B-Application
vision	I-Application
and	O
image	B-Algorithm
processing	I-Algorithm
.	O
</s>
<s>
Python	B-Language
is	O
commonly	O
used	O
in	O
artificial	B-Application
intelligence	I-Application
projects	O
and	O
machine	O
learning	O
projects	O
with	O
the	O
help	O
of	O
libraries	O
like	O
TensorFlow	B-Language
,	O
Keras	B-Algorithm
,	O
Pytorch	B-Algorithm
,	O
and	O
scikit-learn	B-Application
.	O
</s>
<s>
As	O
a	O
scripting	B-Language
language	I-Language
with	O
a	O
modular	B-Architecture
architecture	I-Architecture
,	O
simple	O
syntax	O
,	O
and	O
rich	O
text	B-Device
processing	I-Device
tools	O
,	O
Python	B-Language
is	O
often	O
used	O
for	O
natural	B-Language
language	I-Language
processing	I-Language
.	O
</s>
<s>
Python	B-Language
can	O
also	O
be	O
used	O
to	O
create	O
games	O
,	O
with	O
libraries	O
such	O
as	O
Pygame	B-Operating_System
,	O
which	O
can	O
make	O
2D	O
games	O
.	O
</s>
<s>
Python	B-Language
has	O
been	O
successfully	O
embedded	O
in	O
many	O
software	O
products	O
as	O
a	O
scripting	B-Language
language	I-Language
,	O
including	O
in	O
finite	B-Application
element	I-Application
method	I-Application
software	O
such	O
as	O
Abaqus	B-Algorithm
,	O
3D	O
parametric	O
modelers	O
like	O
FreeCAD	B-Language
,	O
3D	O
animation	O
packages	O
such	O
as	O
3ds	B-Language
Max	I-Language
,	O
Blender	B-Application
,	O
Cinema	B-Device
4D	I-Device
,	O
Lightwave	B-Device
,	O
Houdini	B-Application
,	O
Maya	B-Language
,	O
modo	B-Application
,	O
MotionBuilder	B-Application
,	O
Softimage	B-Device
,	O
the	O
visual	O
effects	O
compositor	O
Nuke	B-Language
,	O
2D	O
imaging	O
programs	O
like	O
GIMP	B-Application
,	O
Inkscape	B-Application
,	O
Scribus	B-Application
and	O
Paint	B-Application
Shop	I-Application
Pro	I-Application
,	O
and	O
musical	O
notation	O
programs	O
like	O
scorewriter	B-Application
and	O
capella	B-Application
.	O
</s>
<s>
GNU	B-Language
Debugger	I-Language
uses	O
Python	B-Language
as	O
a	O
pretty	B-Application
printer	I-Application
to	O
show	O
complex	O
structures	O
such	O
as	O
C++	B-Language
containers	O
.	O
</s>
<s>
Esri	O
promotes	O
Python	B-Language
as	O
the	O
best	O
choice	O
for	O
writing	O
scripts	O
in	O
ArcGIS	B-Application
.	O
</s>
<s>
It	O
has	O
also	O
been	O
used	O
in	O
several	O
video	O
games	O
,	O
and	O
has	O
been	O
adopted	O
as	O
first	O
of	O
the	O
three	O
available	O
programming	O
languages	O
in	O
Google	B-Application
App	I-Application
Engine	I-Application
,	O
the	O
other	O
two	O
being	O
Java	B-Language
and	O
Go	B-Application
.	O
</s>
<s>
Many	O
operating	O
systems	O
include	O
Python	B-Language
as	O
a	O
standard	O
component	O
.	O
</s>
<s>
It	O
ships	O
with	O
most	O
Linux	B-Application
distributions	I-Application
,	O
AmigaOS	B-Application
4	I-Application
(	O
using	O
Python2.7	O
)	O
,	O
FreeBSD	B-Operating_System
(	O
as	O
a	O
package	O
)	O
,	O
NetBSD	B-Device
,	O
and	O
OpenBSD	B-Operating_System
(	O
as	O
a	O
package	O
)	O
and	O
can	O
be	O
used	O
from	O
the	O
command	O
line	O
(	O
terminal	O
)	O
.	O
</s>
<s>
Many	O
Linux	B-Application
distributions	I-Application
use	O
installers	O
written	O
in	O
Python	B-Language
:	O
Ubuntu	B-Operating_System
uses	O
the	O
Ubiquity	B-Language
installer	I-Language
,	O
while	O
Red	O
Hat	O
Linux	B-Application
and	O
Fedora	O
Linux	B-Application
use	O
the	O
Anaconda	B-Language
installer	I-Language
.	O
</s>
<s>
Gentoo	B-Application
Linux	I-Application
uses	O
Python	B-Language
in	O
its	O
package	B-Application
management	I-Application
system	I-Application
,	O
Portage	B-Application
.	O
</s>
<s>
Python	B-Language
is	O
used	O
extensively	O
in	O
the	O
information	O
security	O
industry	O
,	O
including	O
in	O
exploit	O
development	O
.	O
</s>
<s>
Most	O
of	O
the	O
Sugar	B-Language
software	O
for	O
the	O
One	O
Laptop	O
per	O
Child	O
XO	O
,	O
developed	O
at	O
Sugar	B-Language
Labs	O
since	O
2008	O
,	O
is	O
written	O
in	O
Python	B-Language
.	O
</s>
<s>
The	O
Raspberry	B-Operating_System
Pi	I-Operating_System
single-board	B-Device
computer	I-Device
project	O
has	O
adopted	O
Python	B-Language
as	O
its	O
main	O
user-programming	O
language	O
.	O
</s>
<s>
LibreOffice	B-Application
includes	O
Python	B-Language
and	O
intends	O
to	O
replace	O
Java	B-Language
with	O
Python	B-Language
.	O
</s>
<s>
Its	O
Python	B-Language
Scripting	O
Provider	O
is	O
a	O
core	O
feature	O
since	O
Version	O
4.0	O
from	O
7	O
February	O
2013	O
.	O
</s>
<s>
Python	B-Language
's	O
design	O
and	O
philosophy	O
have	O
influenced	O
many	O
other	O
programming	O
languages	O
:	O
</s>
<s>
Boo	B-Application
uses	O
indentation	O
,	O
a	O
similar	O
syntax	O
,	O
and	O
a	O
similar	O
object	O
model	O
.	O
</s>
<s>
Cobra	B-Language
uses	O
indentation	O
and	O
a	O
similar	O
syntax	O
,	O
and	O
its	O
Acknowledgements	O
document	O
lists	O
Python	B-Language
first	O
among	O
languages	O
that	O
influenced	O
it	O
.	O
</s>
<s>
CoffeeScript	B-Application
,	O
a	B-Language
programming	I-Language
language	I-Language
that	O
cross-compiles	O
to	O
JavaScript	B-Language
,	O
has	O
Python-inspired	O
syntax	O
.	O
</s>
<s>
ECMAScript/JavaScript	O
borrowed	O
iterators	O
and	O
generators	O
from	O
Python	B-Language
.	O
</s>
<s>
GDScript	B-Application
,	O
a	O
scripting	B-Language
language	I-Language
very	O
similar	O
to	O
Python	B-Language
,	O
built-in	O
to	O
the	O
Godot	B-Application
game	O
engine	O
.	O
</s>
<s>
Go	B-Application
is	O
designed	O
for	O
the	O
"	O
speed	O
of	O
working	O
in	O
a	O
dynamic	O
language	O
like	O
Python	B-Language
"	O
and	O
shares	O
the	O
same	O
syntax	O
for	O
slicing	O
arrays	O
.	O
</s>
<s>
Groovy	B-Application
was	O
motivated	O
by	O
the	O
desire	O
to	O
bring	O
the	O
Python	B-Language
design	O
philosophy	O
to	O
Java	B-Language
.	O
</s>
<s>
Julia	B-Application
was	O
designed	O
to	O
be	O
"	O
as	O
usable	O
for	O
general	O
programming	O
as	O
Python	B-Language
"	O
.	O
</s>
<s>
Nim	B-Application
uses	O
indentation	O
and	O
similar	O
syntax	O
.	O
</s>
<s>
Ruby	B-Language
's	O
creator	O
,	O
Yukihiro	O
Matsumoto	O
,	O
has	O
said	O
:	O
"	O
I	O
wanted	O
a	O
scripting	B-Language
language	I-Language
that	O
was	O
more	O
powerful	O
than	O
Perl	B-Language
,	O
and	O
more	O
object-oriented	B-Language
than	O
Python	B-Language
.	O
</s>
<s>
Swift	B-Application
,	O
a	B-Language
programming	I-Language
language	I-Language
developed	O
by	O
Apple	O
,	O
has	O
some	O
Python-inspired	O
syntax	O
.	O
</s>
<s>
Python	B-Language
's	O
development	O
practices	O
have	O
also	O
been	O
emulated	O
by	O
other	O
languages	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
practice	O
of	O
requiring	O
a	O
document	O
describing	O
the	O
rationale	O
for	O
,	O
and	O
issues	O
surrounding	O
,	O
a	O
change	O
to	O
the	O
language	O
(	O
in	O
Python	B-Language
,	O
a	O
PEP	O
)	O
is	O
also	O
used	O
in	O
Tcl	B-Operating_System
,	O
Erlang	B-Operating_System
,	O
and	O
Swift	B-Application
.	O
</s>
