Jupyter (IPython) の便利機能¶
入力や出力の参照¶
x, y = 10, 5
x + y
15
x - y
5
x * y
50
x / y
2.0
_, __, ___
(2.0, 50, 5)
In[2]
'x + y'
Out[2]
15
シェルコマンドの実行¶
!ls *.txt
prefecture.txt prefecture3.txt requirements.txt
prefecture2.txt prefecture4.txt tokyo-covid.txt
!cat prefecture.txt
東京 とうきょう Tokyo
神奈川 かながわ Kanagawa
千葉 ちば Chiba
埼玉 さいたま Saitama
!cut -f2 -d" " prefecture.txt
とうきょう
かながわ
ちば
さいたま
yomi = !cut -f2 -d" " prefecture.txt
yomi
['とうきょう', 'かながわ', 'ちば', 'さいたま']
イントロスペクション¶
print?
Docstring:
print(value, ..., sep=' ', end='\n', file=sys.stdout, flush=False)
Prints the values to a stream, or to sys.stdout by default.
Optional keyword arguments:
file: a file-like object (stream); defaults to the current sys.stdout.
sep: string inserted between values, default a space.
end: string appended after the last value, default a newline.
flush: whether to forcibly flush the stream.
Type: builtin_function_or_method
str.format?
Docstring:
S.format(*args, **kwargs) -> str
Return a formatted version of S, using substitutions from args and kwargs.
The substitutions are identified by braces ('{' and '}').
Type: method_descriptor
実行速度の計測¶
%timeit sum(range(1000))
11.1 µs ± 674 ns per loop (mean ± std. dev. of 7 runs, 100000 loops each)
%timeit sum([x for x in range(1000)])
24.3 µs ± 1.01 µs per loop (mean ± std. dev. of 7 runs, 10000 loops each)
%timeit sum(x for x in range(1000))
31 µs ± 298 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)
%%timeit
s = 0
for i in range(1000):
s += i
31.4 µs ± 288 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)
デバッグ¶
def count_upper(s):
n = 0
for c in s:
if c.isupper():
++n
return n
count_upper('New York')
0
%pdb on
Automatic pdb calling has been turned ON
def count_upper(s):
breakpoint()
n = 0
for c in s:
if c.isupper():
++n
return n
count_upper('New York')
> <ipython-input-23-e2234f85ac9f>(3)count_upper()
1 def count_upper(s):
2 breakpoint()
----> 3 n = 0
4 for c in s:
5 if c.isupper():
ipdb> n
> <ipython-input-23-e2234f85ac9f>(4)count_upper()
2 breakpoint()
3 n = 0
----> 4 for c in s:
5 if c.isupper():
6 ++n
ipdb> n
> <ipython-input-23-e2234f85ac9f>(5)count_upper()
3 n = 0
4 for c in s:
----> 5 if c.isupper():
6 ++n
7 return n
ipdb> n
> <ipython-input-23-e2234f85ac9f>(6)count_upper()
3 n = 0
4 for c in s:
5 if c.isupper():
----> 6 ++n
7 return n
ipdb> n
> <ipython-input-23-e2234f85ac9f>(4)count_upper()
2 breakpoint()
3 n = 0
----> 4 for c in s:
5 if c.isupper():
6 ++n
ipdb> p n
0
ipdb> quit
---------------------------------------------------------------------------
BdbQuit Traceback (most recent call last)
<ipython-input-24-ad74a7582071> in <module>
----> 1 count_upper('New York')
<ipython-input-23-e2234f85ac9f> in count_upper(s)
2 breakpoint()
3 n = 0
----> 4 for c in s:
5 if c.isupper():
6 ++n
<ipython-input-23-e2234f85ac9f> in count_upper(s)
2 breakpoint()
3 n = 0
----> 4 for c in s:
5 if c.isupper():
6 ++n
~/anaconda3/lib/python3.8/bdb.py in trace_dispatch(self, frame, event, arg)
86 return # None
87 if event == 'line':
---> 88 return self.dispatch_line(frame)
89 if event == 'call':
90 return self.dispatch_call(frame, arg)
~/anaconda3/lib/python3.8/bdb.py in dispatch_line(self, frame)
111 if self.stop_here(frame) or self.break_here(frame):
112 self.user_line(frame)
--> 113 if self.quitting: raise BdbQuit
114 return self.trace_dispatch
115
BdbQuit:
> /home/okazaki/anaconda3/lib/python3.8/bdb.py(113)dispatch_line()
111 if self.stop_here(frame) or self.break_here(frame):
112 self.user_line(frame)
--> 113 if self.quitting: raise BdbQuit
114 return self.trace_dispatch
115
ipdb> quit
sum(1 for c in 'New York' if c.isupper())
2