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数据为下面的csv文件
通过padas和os读取该文件,代码如下
import pandas as pd
dir = 'shiyan.csv'
df = pd.read_csv(dir)
data1 = df[df.b.notnull()].loc[:,:]
print('data1:')
print(data1)
data2 = df[df.b.astype(str) != 'nan'].loc[:,:]
print('data2:')
print(data2)
print('df[df.notnull()]:')
print(df[df.notnull()])
print('df.notnull:')
print(df.notnull())
print('os.read:')
with open(dir, 'r') as f:
for line in f.readlines():
print(line, end='')
运行结果如下图:
可以看看结果,记住结论。其中notnull()和notna()是等价的,那么isnull()和isna()应该也是等价的
补充一种情况,如下所示
data3 = df[df.b.astype(str) != 'null'].loc[:, :]
print('data3:')
print(data3)