内容 - python语法判空

例子

import pandas as pd
import numpy as np
data = [{"a":"nan","b":np.nan,"c":None,}]
df = pd.DataFrame(data=data, )
print(df)

“nan”

print("-------a-------")
print(df.iloc[0,:]['a'])
print(type(df.iloc[0,:]['a']))
if df.iloc[0,:]['a']:
    print("a")  # 到此
if df.iloc[0,:]['a'] == "nan":
    print("a2")  # 到此
if df.iloc[0,:]['a'] == np.nan:
    print("a3")
if df.iloc[0,:]['a'] == "None":
    print("a4")
if df.iloc[0,:]['a'] == None:
    print("a5")

np.nan

print("-------b-------")
print(df.iloc[0,:]['b'])
print(type(df.iloc[0,:]['b']))
if df.iloc[0,:]['b']:
    print("b")  # 到此
if df.iloc[0,:]['b'] == "nan":
    print("b2")
if df.iloc[0,:]['b'] == np.nan:
    print("b3")
if df.iloc[0,:]['b'] == "None":
    print("b4")
if df.iloc[0,:]['b'] == None:
    print("b5")

None

print("-------c-------")
print(df.iloc[0,:]['c'])
print(type(df.iloc[0,:]['c']))
if df.iloc[0,:]['c']:
    print("c")
if df.iloc[0,:]['c'] == "nan":
    print("c2")
if df.iloc[0,:]['c'] == np.nan:
    print("c3")
if df.iloc[0,:]['c'] == "None":
    print("c4")
if df.iloc[0,:]['c'] == None:
    print("c5")  # 到此

空

data = Series['列名']
if pd.isnull(data):
    return "空的"