Using str.contains on pandas dataframe [duplicate] Using str.contains on pandas dataframe [duplicate] arrays arrays

Using str.contains on pandas dataframe [duplicate]


Credit to Davtho1983 comment above, I thought I'd add color to the comment for clarity.

For anyone stumbling on this later with the same error (like me).It's a very simple fix. The documentation from pandas shows

Series.str.contains(pat, case=True, flags=0, na=nan, regex=True)

What's happening is the contains() method isn't being applied to na values in the DataFrame, they will remain na. You just need to fill na values with Boolean values so you may use the invert operator ~ .

With the example above one should use

df_Anomalous_Vendor_Reasons[~df_Anomalous_Vendor_Reasons['V'].str.contains("File*|registry*", na=False)]

Of course one should choose False or True for the na argument based on intended logic. Whichever Boolean value you choose for filling na will be inverted.