pandas join DataFrame force suffix?

Question

How can I force a suffix on a merge or join. I understand it\'s possible to provide one if there is a collision but in my case I\'m merging df1 with df2 which doesn\'t cause an

Answer 1

This is what I've been using to pandas.merge two DataFrames and force suffixing:

def merge_force_suffix(left, right, **kwargs):
    on_col = kwargs['on']
    suffix_tupple = kwargs['suffixes']

    def suffix_col(col, suffix):
        if col != on_col:
            return str(col) + suffix
        else:
            return col

    left_suffixed = left.rename(columns=lambda x: suffix_col(x, suffix_tupple[0]))
    right_suffixed = right.rename(columns=lambda x: suffix_col(x, suffix_tupple[1]))
    del kwargs['suffixes']
    return pd.merge(left_suffixed, right_suffixed, **kwargs)