<s>
scikit-learn	B-Application
(	O
formerly	O
scikits.learn	B-Application
and	O
also	O
known	O
as	O
sklearn	B-Application
)	O
is	O
a	O
free	B-Application
software	I-Application
machine	O
learning	O
library	B-Library
for	O
the	O
Python	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
It	O
features	O
various	O
classification	B-General_Concept
,	O
regression	O
and	O
clustering	B-Algorithm
algorithms	I-Algorithm
including	O
support-vector	B-Algorithm
machines	I-Algorithm
,	O
random	B-Algorithm
forests	I-Algorithm
,	O
gradient	B-Algorithm
boosting	I-Algorithm
,	O
k-means	B-Algorithm
and	O
DBSCAN	B-Algorithm
,	O
and	O
is	O
designed	O
to	O
interoperate	O
with	O
the	O
Python	B-Language
numerical	O
and	O
scientific	O
libraries	O
NumPy	B-Application
and	O
SciPy	B-Application
.	O
</s>
<s>
Scikit-learn	B-Application
is	O
a	O
NumFOCUS	O
fiscally	O
sponsored	O
project	O
.	O
</s>
<s>
The	O
scikit-learn	B-Application
project	O
started	O
as	O
scikits.learn	B-Application
,	O
a	O
Google	B-Application
Summer	I-Application
of	I-Application
Code	I-Application
project	O
by	O
French	O
data	O
scientist	O
David	O
Cournapeau	O
.	O
</s>
<s>
The	O
name	O
of	O
the	O
project	O
stems	O
from	O
the	O
notion	O
that	O
it	O
is	O
a	O
"	O
SciKit	O
"	O
(	O
SciPy	B-Application
Toolkit	O
)	O
,	O
a	O
separately	O
developed	O
and	O
distributed	O
third-party	O
extension	O
to	O
SciPy	B-Application
.	O
</s>
<s>
The	O
original	O
codebase	B-General_Concept
was	O
later	O
rewritten	O
by	O
other	O
developers	O
.	O
</s>
<s>
In	O
2010	O
,	O
contributors	O
Fabian	O
Pedregosa	O
,	O
Gaël	O
Varoquaux	O
,	O
Alexandre	O
Gramfort	O
and	O
Vincent	O
Michel	O
,	O
from	O
the	O
French	O
Institute	O
for	O
Research	O
in	O
Computer	O
Science	O
and	O
Automation	O
in	O
Saclay	O
,	O
France	O
,	O
took	O
leadership	O
of	O
the	O
project	O
and	O
released	O
the	O
first	O
public	O
version	O
of	O
the	O
library	B-Library
on	O
February	O
1	O
,	O
2010	O
.	O
</s>
<s>
In	O
November	O
2012	O
,	O
scikit-learn	B-Application
as	O
well	O
as	O
scikit-image	B-Library
,	O
were	O
described	O
as	O
two	O
of	O
the	O
"	O
well-maintained	O
and	O
popular	O
"	O
.	O
</s>
<s>
In	O
2019	O
,	O
it	O
was	O
noted	O
that	O
scikit-learn	B-Application
is	O
one	O
of	O
the	O
most	O
popular	O
machine	O
learning	O
libraries	O
on	O
GitHub	B-Application
.	O
</s>
<s>
scikit-learn	B-Application
is	O
largely	O
written	O
in	O
Python	B-Language
,	O
and	O
uses	O
NumPy	B-Application
extensively	O
for	O
high-performance	O
linear	O
algebra	O
and	O
array	O
operations	O
.	O
</s>
<s>
Furthermore	O
,	O
some	O
core	O
algorithms	O
are	O
written	O
in	O
Cython	B-Application
to	O
improve	O
performance	O
.	O
</s>
<s>
Support	B-Algorithm
vector	I-Algorithm
machines	I-Algorithm
are	O
implemented	O
by	O
a	O
Cython	B-Application
wrapper	O
around	O
LIBSVM	B-Language
;	O
logistic	O
regression	O
and	O
linear	O
support	B-Algorithm
vector	I-Algorithm
machines	I-Algorithm
by	O
a	O
similar	O
wrapper	O
around	O
LIBLINEAR	B-Language
.	O
</s>
<s>
In	O
such	O
cases	O
,	O
extending	O
these	O
methods	O
with	O
Python	B-Language
may	O
not	O
be	O
possible	O
.	O
</s>
<s>
scikit-learn	B-Application
integrates	O
well	O
with	O
many	O
other	O
Python	B-Language
libraries	O
,	O
such	O
as	O
Matplotlib	B-Language
and	O
plotly	B-Application
for	O
plotting	O
,	O
NumPy	B-Application
for	O
array	O
vectorization	O
,	O
Pandas	B-Application
dataframes	O
,	O
SciPy	B-Application
,	O
and	O
many	O
more	O
.	O
</s>
<s>
scikit-learn	B-Application
was	O
initially	O
developed	O
by	O
David	O
Cournapeau	O
as	O
a	O
Google	B-Application
Summer	I-Application
of	I-Application
Code	I-Application
project	O
in	O
2007	O
.	O
</s>
