Use sep=r'\s*,\s*' to parse a file where the columns may have some number of spaces preceding or following the delimiter (e.g. , ):
transactions = pd.read_csv('transactions.csv', sep=r'\s*,\s*',
header=0, encoding='ascii', engine="python")
Prove:
print(transactions.columns)
Output:
Index(['product_id', 'customer_id', 'store_id', 'promotion_id', 'month_of_year', 'quarter', 'the_year', 'store_sales', 'store_cost', 'unit_sales', 'fact_count'], dtype="object")
Alternatively, remove unquoted spaces in the CSV file, and use your command (unchanged).