python - Pandaic way to check whether a dataframe has any rows -

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• how check whether pandas dataframe empty? 3 answers

given dataframe df, i'd apply condition df[condition] , retrieve subset. want check if there rows in subset - tell me condition valid one.

in [551]: df out[551]:     col1 0     1 1     2 2     3 3     4 4     5 5     3 6     1 7     2 8     3 

what want check this:

if df[condition] has rows:     

what best way check whether filtered dataframe has rows? here's methods don't work:

1. if df[df.col1 == 1]: gives valueerror: truth value of dataframe ambiguous.

2. if df[df.col1 == 1].any(): gives valueerror

i suppose can test len. there other ways?

you use df.empty:

df_conditional = df.loc[df['column_name'] == some_value] if not df_conditional.empty:     ... # process dataframe results