How to find a columns set for a primary key candidate in CSV file?

Question

I have a CSV file (not normalized, example, real file up to 100 columns):

   ID, CUST_NAME, CLIENT_NAME, PAYMENT_NUM, START_DATE, END_DATE
    1,     CUST1,         


        

Answer 1

This is one way via itertools.combinations. It works by, for each set of columns, dropping duplicates and checking if the size of the dataframe changes.

This results in 44 distinct combinations of columns.

from itertools import combinations, chain

full_list = chain.from_iterable(combinations(df, i) for i in range(1, len(df.columns)+1))

n = len(df.index)

res = []
for cols in full_list:
    cols = list(cols)
    if len(df[cols].drop_duplicates().index) == n:
        res.append(cols)

print(len(res))  # 44