df.loc[index, 'col name']
は、あなたが行に
デモをフィルタリングする場合は特に、より多くの慣用的かつ好ましいです:あなたは1列のみとドン」を必要とする工事については1.000.000×3形DF
In [26]: df = pd.DataFrame(np.random.rand(10**6,3), columns=list('abc'))
In [27]: %timeit df[df.a < 0.5]['a']
10 loops, best of 3: 45.8 ms per loop
In [28]: %timeit df.loc[df.a < 0.5]['a']
10 loops, best of 3: 45.8 ms per loop
In [29]: %timeit df.loc[df.a < 0.5, 'a']
10 loops, best of 3: 37 ms per loop
用multipの
In [30]: %timeit df[:]['a']
1000 loops, best of 3: 436 µs per loop
In [31]: %timeit df.loc[:]['a']
10000 loops, best of 3: 25.9 µs per loop
In [36]: %timeit df['a'].loc[:]
10000 loops, best of 3: 26.5 µs per loop
In [32]: %timeit df.loc[:, 'a']
10000 loops, best of 3: 126 µs per loop
In [33]: %timeit df['a']
The slowest run took 5.08 times longer than the fastest. This could mean that an intermediate result is being cached.
100000 loops, best of 3: 8.17 µs per loop
Uncoditionalアクセス:それは単にdf['Store']
を使用することをお勧めします - df[:]['Store']
のようなTフィルタ行列:
In [34]: %timeit df[['a','b']]
10 loops, best of 3: 22 ms per loop
In [35]: %timeit df.loc[:, ['a','b']]
10 loops, best of 3: 22.6 ms per loop