Search for does-not-contain on a DataFrame in pandas

Question

I ve done some searching and can t figure out how to filter a dataframe by df  col   str contains word   however I m wondering if there is a way to do the reverse  filter a dataframe by that set s compliment  eg  to the effect of   df  col   str contains word      Can this be done through a DataFrame method

User · Answer

I hope the answers are already posted

I am adding the framework to find multiple words and negate those from dataFrame.

Here 'word1','word2','word3','word4' = list of patterns to search

df = DataFrame

column_a = A column name from from DataFrame df

Search_for_These_values = ['word1','word2','word3','word4'] 

pattern = '|'.join(Search_for_These_values)

result = df.loc[~(df['column_a'].str.contains(pattern, case=False)]

User · Answer

You can use Apply and Lambda to select rows where a column contains any thing in a list  For your scenario    df df  col   apply lambda x x not in  word1 word2 word3

User · Answer

I had to get rid of the NULL values before using the command recommended by Andy above  An example   df   pd DataFrame index    0  1  2   columns   first    second    third    df ix     first      myword  df ix 0   second      myword  df ix 2   second      myword  df ix 1   third      myword  df      first   second  third 0   myword  myword   NaN 1   myword  NaN      myword  2   myword  myword   NaN   Now running the command    df  second   str contains word    I get the following error   TypeError  bad operand type for unary     float    I got rid of the NULL values using dropna   or fillna   first and retried the command with no problem

User · Answer

I was having trouble with the not     symbol as well  so here s another way from another StackOverflow thread   df df  col   str contains  this that    False

User · Answer

Additional to nanselm2 s answer  you can use 0 instead of False   df  col   str contains word   0

User · Answer

You can use the invert     operator  which acts like a not for boolean data    new df   df  df  col   str contains word       where new df is the copy returned by RHS   contains also accepts a regular expression       If the above throws a ValueError  the reason is likely because you have mixed datatypes  so use na False   new df   df  df  col   str contains word  na False     Or   new df   df df  col   str contains word     False

[python] Search for "does-not-contain" on a DataFrame in pandas

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