How to add headers when creating csv file in python

Question

I am getting "raw" data from a csv file, and putting only what I need for a new csv file that will be used to auto add users to a different system...

I am unsure how to add the correct headers needed for the file.

I've tried looking at other examples of adding headers but have not figured this out yet...

The headers I need to add are as follows:

"ID Card Number","Name","E-Mail","User Level","Position","Status","Covered Under Insurance","Paid Insurance"

(and in that order)

import csv


def studentscsv():
    with open('..\StudentEmails_and_StudentNumbers.csv') as csv_file:
        csv_reader = csv.reader(csv_file, delimiter=',')
        with open('mydirectory\student_users.csv', mode='w', newline='') as output_file:
            write = csv.writer(output_file, delimiter=',', quoting=csv.QUOTE_MINIMAL)
            for row in csv_reader:
                a = row[0]
                studentnumber = row[1]
                firstname = row[2]
                lastname = row[3]
                grade = row[4]
                studentname = firstname + " " + lastname
                studentemail = firstname + "." + lastname + "@mydomain.org"
                status = "Active"
                position = "Student"
                covered = "Yes"
                paid = "Yes"


                write.writerow([studentnumber, studentname, studentemail, grade, position, status, covered, paid])


def main():
    """
    Controls the program execution
    :param in_file: the name of the input file.
    :return: None
    """


if __name__ == '__main__':
    main()

The file generates fine with the way the code is written. I am just unsure what I need to change to add the headers.

Possible duplicate of [Pythonically add header to a csv file](https://stackoverflow.com/questions/20347766/pythonically-add-header-to-a-csv-file) — Mihai Chelaru, Jan 18 '19 at 19:13
@MihaiChelaru I respectfully disagree with that assertion as that example is combining data from two different csv files and adding that data and headers to different named csv file. I am simply trying to include headers in the csv file I am generating. — Joseph Sanders, Jan 18 '19 at 19:20

Sebastian Scholl · Answer 1 · 2019-01-18T19:23:22.763

4

Using the csv module, as you are, it's pretty straight forward. Define your headers in an array and then create a DictWriter with the fieldnames set to your array. Reference the following code and documentation:

  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'})

Here's the documentation:

https://docs.python.org/2/library/csv.html#csv.DictWriter

edited Jan 18 '19 at 19:23

answered Jan 18 '19 at 19:18

Sebastian Scholl

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Thanks... For some reason I am not seeing the documentation you mentioned? – Joseph Sanders Jan 18 '19 at 19:22
So I am just a bit confused in that example.... If you define fieldnames as ['first_name', 'last_name'], then why do you need to tell it to write the name of each field before the data? – Joseph Sanders Jan 18 '19 at 19:51
You're specifying which column each piece of data goes into by column name for each row. So, for example, `writer.writerow({'first_name': 'Baked', 'last_name': 'Beans'})` is specifying that "Baked" goes in the First_name column and that "Beans" goes in the last name column. – Sebastian Scholl Jan 18 '19 at 22:45
Just to be extra clear on this... `fieldnames = ['first_name', 'last_name']` is a List of column names (header names). What's being passed to `writerow` is an Dictionary `{'first_name': 'Baked', 'last_name': 'Beans'}`. You're **NOT** telling to to write the name of each field before the data. You **ARE** specifying which field each piece of data belongs to. – Sebastian Scholl Jan 18 '19 at 22:50

How to add headers when creating csv file in python

1 Answers1