Join a list (dict) of pandas dataframes

multi_df_join.py

import pandas
import logging

def multi_df_join(df_dict):
    """
    Takes a list of dataframes with the same primary key (id) and merges the columns, using
    the dictionary keys as suffixes in case there are conflicts with the column names.

    :param df_dict: A dictionary where keys are strings (collision suffixes) and values are DataFrames
    :return pandas.DataFrame: The merged data frames
    """

    # check if there are colliding column names
    all_columns = []
    for df in df_dict.values():
        all_columns = all_columns + list(df.columns)
    colliding_columns = set([x for x in all_columns if all_columns.count(x) > 1])

    df = None
    for suffix, input_df in df_dict.items():

        # rename colliding columns
        renamer_dict = {}
        for col in list(input_df.columns):
            if col in colliding_columns:
                renamer_dict[col] = col + suffix
        input_df.rename(columns=renamer_dict, inplace=True)

        # join columns
        if df is None:
            df = input_df
        else:
            df = df.join(input_df, how='outer')
        logging.debug("Shape is currently: {}".format(df.shape))

    return df