Search for String in all Pandas DataFrame columns and filter

Question

Thought this would be straight forward but had some trouble tracking down an elegant way to search all columns in a dataframe at same time for a partial string match. Basically how would I apply df['col1'].str.contains('^') to an entire dataframe at once and filter down to any rows that have records containing the match?

Answer 1

The Series.str.contains method expects a regex pattern (by default), not a literal string. Therefore str.contains("^") matches the beginning of any string. Since every string has a beginning, everything matches. Instead use str.contains("\^") to match the literal ^ character.

To check every column, you could use for col in df to iterate through the column names, and then call str.contains on each column:

mask = np.column_stack([df[col].str.contains(r"\^", na=False) for col in df])

df.loc[mask.any(axis=1)]

Alternatively, you could pass regex=False to str.contains to make the test use the Python in operator; but (in general) using regex is faster.