<s>
The	O
Natural	B-General_Concept
Language	I-General_Concept
Toolkit	I-General_Concept
,	O
or	O
more	O
commonly	O
NLTK	B-General_Concept
,	O
is	O
a	O
suite	O
of	O
libraries	B-Library
and	O
programs	O
for	O
symbolic	O
and	O
statistical	O
natural	B-Language
language	I-Language
processing	I-Language
(	O
NLP	B-Language
)	O
for	O
English	O
written	O
in	O
the	O
Python	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
NLTK	B-General_Concept
includes	O
graphical	O
demonstrations	O
and	O
sample	O
data	O
.	O
</s>
<s>
NLTK	B-General_Concept
is	O
intended	O
to	O
support	O
research	O
and	O
teaching	O
in	O
NLP	B-Language
or	O
closely	O
related	O
areas	O
,	O
including	O
empirical	O
linguistics	O
,	O
cognitive	O
science	O
,	O
artificial	B-Application
intelligence	I-Application
,	O
information	B-Library
retrieval	I-Library
,	O
and	O
machine	O
learning	O
.	O
</s>
<s>
NLTK	B-General_Concept
has	O
been	O
used	O
successfully	O
as	O
a	O
teaching	O
tool	O
,	O
as	O
an	O
individual	O
study	O
tool	O
,	O
and	O
as	O
a	O
platform	O
for	O
prototyping	O
and	O
building	O
research	O
systems	O
.	O
</s>
<s>
There	O
are	O
32	O
universities	O
in	O
the	O
US	O
and	O
25	O
countries	O
using	O
NLTK	B-General_Concept
in	O
their	O
courses	O
.	O
</s>
<s>
NLTK	B-General_Concept
supports	O
classification	O
,	O
tokenization	O
,	O
stemming	O
,	O
tagging	O
,	O
parsing	O
,	O
and	O
semantic	O
reasoning	O
functionalities	O
.	O
</s>
