# fileparse.py

#

# Exercise 3.3

import csv

def parse_csv(

filename,

select=None,

types=None,

has_headers=True,

delimiter=",",

silence_errors=False,

):

"""

Parse a CSV file into a list of records

"""

if select and not has_headers:

raise RuntimeError("select requires column headers")

with open(filename, "r") as f:

rows = csv.reader(f, delimiter=delimiter)

# Read the file headers if there are any

headers = next(rows) if has_headers else []

# If a column selector was given, find indices of the specified columns.

# Also narrow the set of headers used for resulting dictionaries

if select:

indices = [headers.index(colname) for colname in select]

headers = select

else:

indices = []

records = []

for rowno, row in enumerate(rows, 1):

if not row:

continue

# Filter the row if specific columns were selected

if select:

row = [row[index] for index in indices]

if types:

try:

row = [func(val) for func, val in zip(types, row)]

except ValueError as e:

if not silence_errors:

print(f"Row {rowno}: Couldn't convert {row}")

print(f"Row {rowno}: Reason {e}")

continue

# Make a dictionary or a tuple

if headers:

record = dict(zip(headers, row))

else:

record = tuple(row)

records.append(record)

return records