This document discusses how to process CSV files in Python. It begins by explaining why Python is a useful language, then describes what CSV files are and where they come from. It explains that the csv library in Python allows reading from and writing to CSV files. It provides sample code to read a CSV file containing employee data and print out the information, as well as code to write new employee data to a CSV file.

1. How to process
CSV file in Python?
By
Tukaram Bhagat

2. Why Learn Python?
• Python is a general-purpose, versatile and
popular programming language. It's great as a
first language because it is concise and easy to
read, and it is also a good language to have in
any programmer's stack as it can be used for
everything from web development to
software development and data science
applications.

3. Take-Away Skills
• This course is a great introduction to both
fundamental programming concepts and the
Python programming language. Python 3 is
the most up-to-date version of the language
with many improvements made to increase
the efficiency and simplicity of the code that
you write.

4. What Is a CSV File?
A CSV file (Comma Separated Values file) is a
plain text file that uses specific structuring to
arrange tabular data.
It can contain only actual text
printable ASCII or Unicode characters.

5. Where Do CSV Files Come From?
• CSV files are normally created by programs
that handle large amounts of data.
• They are a convenient way to export data
from spreadsheets and databases as well as
import or use it in other programs.

6. Parsing CSV Files With Python’s Built-
in CSV Library
• The csv library provides functionality to both
read from and write to CSV files.
• The csv library contains objects and other
code to read, write, and process data from
and to CSV files.

7. Reading CSV Files With csv
Here’s the employee_birthday.txt file:
Name,Department,Birthday Month
John Smith,Accounting,November
Erica Meyers,IT,March

8. Here’s code to read it:
import csv
with open('employee_birthday.txt') as csv_file:
csv_reader = csv.reader(csv_file , delimiter=',')
line_count = 0
for row in csv_reader:
if line_count == 0:
print(f'Column names are {", ".join(row)}')
line_count += 1
else:
print(f't{row[0]} works in the {row[1]} department, and was born in
{row[2]}.')
line_count += 1
print(f'Processed {line_count} lines.')

9. Writing CSV Files With csv
import csv
with open('employee_file.csv', mode='w') as employee_file:
employee_writer = csv.writer(employee_file , delimiter=',',
quotechar='"', quoting=csv.QUOTE_MINIMAL)
employee_writer.writerow(['John Smith', 'Accounting',
'November'])
employee_writer.writerow(['Erica Meyers', 'IT', 'March'])