python 布爾切片

import numpy as np
import pandas as pd
# ndarray 布爾切片:
arr = np.arange(10)
print("arr[(arr>2)]: ", arr[(arr>2)])
print("arr[(arr>2) & (arr<6)]: ", arr[(arr>2) & (arr<6)])

# DataFrame 布爾切片:
df = data = pd.DataFrame({'a':np.arange(10),'b':np.arange(15,25)})
print("df[(df.a>2)]:\n", df[(df.a>2)])
print("df[(df.a>2) & (df.a<6)]:\n", df[(df.a>2) & (df.a<6)])
print("df.loc[(df.a>2) & (df.a<6)]:\n", df.loc[(df.a>2) & (df.a<6)])

# Series 布爾切片:
se = pd.Series(np.arange(10))
print("se[(se>2)]: ", se[(se>2)])
print("se[(se>2) & (se<6)]: ", se[(se>2) & (se<6)])
print("se.loc[(se>2) & (se<6)]: ", se.loc[(se>2) & (se<6)])

# list 不支持布爾切片:
l = list(range(10))
print("l[l<5]: ", l[l<5])
print("l[(l>2) & (l<5)]: ", l[(l>2) & (l<5)])