Skip the header of a file with CSV Reader in Python

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# Skip the header of a file with CSV Reader in Python

To skip the header of a file with CSV reader in Python:

Open the csv file in r (reading) mode.
Use the csv.reader() method to get an iterator of the file's contents.
Use the next(csv_reader) method to skip the header of the file.

Here is the employees.csv file for the examples.

employees.csv

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first_name,last_name,date
Alice,Smith,01/21/1995 14:32:44.042010
Bobby,Hadz,04/14/1998 12:51:42.014000
Carl,Lemon,06/11/1994 15:52:43.016000

And here is the code for the main.py file.

main.py

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import csv

with open('employees.csv', 'r', encoding='utf-8') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')

    next(csv_reader)

    for row in csv_reader:
        print(row)

The code for this article is available on GitHub

Running the code produces the following output.

main.py

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['Alice', 'Smith', '01/21/1995 14:32:44.042010']
['Bobby', 'Hadz', '04/14/1998 12:51:42.014000']
['Carl', 'Lemon', '06/11/1994 15:52:43.016000']

skip header of file with csv reader in python

We opened the csv file in r (reading) mode.

The csv.reader() method returns a reader object that iterates over the lines in the CSV file.

To be more precise, the method returns an iterator of lists where each list contains the fields of the given row.

The first item in the list is the header.

You can use the next() function to skip the headers.

main.py

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next(csv_reader)

The next() function returns the next item from the provided iterator.

The function can be passed a default value as the second argument.

If the iterator is exhausted or empty, the default value is returned.

If the iterator is exhausted or empty and no default value is provided, a StopIteration exception is raised.

You can set the default value to None if you want to avoid getting an error if the CSV file is empty.

main.py

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import csv

with open('employees.csv', 'r', encoding='utf-8') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')

    next(csv_reader, None)

    # ['Alice', 'Smith', '01/21/1995 14:32:44.042010']
    # ['Bobby', 'Hadz', '04/14/1998 12:51:42.014000']
    # ['Carl', 'Lemon', '06/11/1994 15:52:43.016000']
    for row in csv_reader:
        print(row)

The code for this article is available on GitHub

You can then use a for loop to iterate over the iterator.

main.py

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# ['Alice', 'Smith', '01/21/1995 14:32:44.042010']
# ['Bobby', 'Hadz', '04/14/1998 12:51:42.014000']
# ['Carl', 'Lemon', '06/11/1994 15:52:43.016000']
for row in csv_reader:
    print(row)

# Skip the header of a file with CSV Reader when using open() directly

The example from the previous subheading uses the with open statement to automatically close the CSV file once we're done.

However, you can also use the open() function directly.

main.py

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import csv

csv_file = open('employees.csv', 'r', encoding='utf-8')
csv_reader = csv.reader(csv_file, delimiter=',')

next(csv_reader, None)

# ['Alice', 'Smith', '01/21/1995 14:32:44.042010']
# ['Bobby', 'Hadz', '04/14/1998 12:51:42.014000']
# ['Carl', 'Lemon', '06/11/1994 15:52:43.016000']
for row in csv_reader:
    print(row)

csv_file.close()

skip header by using open directly

The code for this article is available on GitHub

It is recommended to use the with open() statement because it takes care of automatically closing the file even if an error occurs.

However, if you decide to use the open() function directly, make sure to close the CSV file.

main.py

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csv_file.close()

If you don't close the CSV file when using open() directly, you'll get a memory leak.

# Skip the header of a file with CSV Reader using `islice()`

You can also use the itertools.islice() method to skip the header of a file with CSV reader.

The example uses the same employees.csv file.

employees.csv

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first_name,last_name,date
Alice,Smith,01/21/1995 14:32:44.042010
Bobby,Hadz,04/14/1998 12:51:42.014000
Carl,Lemon,06/11/1994 15:52:43.016000

Here is the related Python code.

main.py

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import csv
from itertools import islice


with open('employees.csv', 'r', encoding='utf-8') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')

    for row in islice(csv_reader, 1, None):
        # ['Alice', 'Smith', '01/21/1995 14:32:44.042010']
        # ['Bobby', 'Hadz', '04/14/1998 12:51:42.014000']
        # ['Carl', 'Lemon', '06/11/1994 15:52:43.016000']

        print(row)

skip headers when processing csv file using islice

The code for this article is available on GitHub

We used the itertools.islice() method instead of using next().

The itertools.islice class takes an iterator and optional start, stop and step values.

The second argument we passed to the islice() class is the index of the first element to be included in the slice.

The third argument is the index of the first element to be excluded from the slice.

We used a value of None because we didn't want to exclude any elements from the slice.

# Skip the header of a file with CSV Reader using `DictReader`

You can also use the csv.DictReader class to skip the header of a file.

main.py

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import csv


with open('employees.csv', 'r', encoding='utf-8') as csv_file:
    dict_reader = csv.DictReader(csv_file, delimiter=',')

    for row in dict_reader:
        print(row['first_name'], row['last_name'], row['date'])

Running the script with python main.py produces the following output.

shell

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Alice Smith 01/21/1995 14:32:44.042010
Bobby Hadz 04/14/1998 12:51:42.014000
Carl Lemon 06/11/1994 15:52:43.016000

using dict reader class to skip header of csv file

The code for this article is available on GitHub

The csv.DictReader class creates an object that operates like a regular reader but it maps the contents of each row in a dictionary.

Note that you have to omit the fieldnames parameter when instantiating DictReader.

If the fieldnames parameter is omitted, the values in the first row are used as the field names.

# Additional Resources

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Skip the header of a file with CSV Reader in Python

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