# fileparse.py

#Reading CSV Files

# Exercise 3.3

import os

import csv

def parse_csv(filename):

'''

Parse a csv file ito a list of records

'''

records = []

with open(filename,'rt+') as f:

rows = csv.reader(f)

headers = next(rows)

for row in rows:

rec = dict(zip(headers,row))

records.append(rec)

print(rec)

return records

workdir = os.getcwd()

workdir += r'\work'

def parse_csv2(filename, select=None):

records = []

with open(filename,'rt+') as g:

rows = csv.reader(g)

header = next(rows)

if select:

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

header = select

else:

indices = []

#hdr2 = [header2[0],header2[1]]

for row in rows:

if not row:

continue

if indices:

row = [row[index] for index in indices] #dict(zip(select,row))

rec = dict(zip(header,row))

records.append(rec)

return records

''''

method callers

'''

recs = parse_csv(workdir+r'\data\portfolio.csv')

recs2 = parse_csv2(workdir+r'\data\portfolio.csv',['name','shares'])

print()

print("-------------\n")

for r in recs2:

print(r)

'''

3.5 Main Module

Python has no main function or method. Instead, there is a main module. The main module is the source file that runs first.

__main__ check

It is standard practice for modules that run as a main script to use this convention:

Main programs vs. library imports

Any Python file can either run as main or as a library import:

bash % python3 prog.py # Running as main

import prog # Running as library import

'''

'''

Python Program Template -- order

'''

# prog.py

# Import statements (libraries)

# Functions

def spam():

...

def blah():

...

# Main function

def main():

...

if __name__ == '__main__':

main()