选择数据 - df[] - df[选择指定列]

作用：显示什么列

import numpy as np
import pandas as pd
df = pd.DataFrame(data=[{"A":"1", "B":"3", "C":"4"}, {"A":"3", "B":"2", "C":"5"}, {"A":"2", "B":"1", "C":"6"}])
df = pd.DataFrame(data=[{"A":1, "B":3, "C":4}, {"A":3, "B":2, "C":5}, {"A":2, "B":1, "C":6}])

指定列df[‘A’,’B’,’C’,’D’]

print(df['B'])

Name: B, dtype: int64

df[['B','C']]