python csv write header code example

Example 1: csv python write

import csv

with open('names.csv', 'w') as csvfile:
    fieldnames = ['first_name', 'last_name']
    writer = csv.DictWriter(csvfile, fieldnames=fieldnames)

    writer.writeheader()
    writer.writerow({'first_name': 'Baked', 'last_name': 'Beans'})
    writer.writerow({'first_name': 'Lovely', 'last_name': 'Spam'})
    writer.writerow({'first_name': 'Wonderful', 'last_name': 'Spam'})

Example 2: python csv dict reader

>>> import csv
>>> with open('names.csv', newline='') as csvfile:
...     reader = csv.DictReader(csvfile)
...     for row in reader:
...         print(row['first_name'], row['last_name'])
...
Eric Idle
John Cleese

>>> print(row)
{'first_name': 'John', 'last_name': 'Cleese'}

Example 3: how to add header in csv file in python

#header in csv file
import pandas as pd
import csv
df = pd.read_csv("file.csv", header=None)
df.to_csv("file.csv", header=["SEQUENCE"], index=False)#header added
df = pd.read_csv("file.csv")
df

Example 4: how to add header in csv file in python

from pandas import read_csv

   df = read_csv('test.csv')
   df.columns = ['a', 'b']
   df.to_csv('test_2.csv')