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  • Post category:Pandas
  • Post last modified:March 27, 2024
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You are currently viewing How to read CSV without headers in pandas

To read a CSV file without headers use the None value to header param in the Pandas read_csv() function. In this article, I will explain different header param values {int, list of int, None, default ‘infer’} that support how to load CSV with headers and with no headers.

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1. Read CSV without Headers

By default, Pandas consider CSV files with headers (it uses the first line of a CSV file as a header record), in case you want to read a CSV file without headers use header=None param.

read csv without header
CSV without header

When header=None used, it considers the first record as a data record.


# Read csv without header
df = pd.read_csv('/Users/admin/apps/courses.csv', header=None)
print(df)

Yields below output.

0 1 2 3 0 Spark 25000 50 Days 2000 1 Pandas 20000 35 Days 1000 2 Java 15000 NaN 800 3 Python 15000 30 Days 500 4 PHP 18000 30 Days 800

2. Set Header Names

When the header is ignored it assigns numerical numbers as column names. To fix this read_csv() function provides a param names to assign custom column names while reading.


# Set Header Names
columns = ['courses','course_fee','course_duration','course_discount']
df = pd.read_csv('/Users/admin/apps/courses.csv', header=None, names=columns)
print(df)

Yields below output.


# Output:
   courses course_fee course_duration course_discount
0    Spark      25000         50 Days            2000
1   Pandas      20000         35 Days            1000
2     Java      15000             NaN             800
3   Python      15000         30 Days             500
4      PHP      18000         30 Days             800

3. Pandas Read CSV with Header

As I said above, by default it reads the CSV with a header (Considers the first row as header). If you have wanted to consider at Nth row use header=N param (replace N according to your need).


# Pandas Read CSV with Header
df = pd.read_csv('/Users/admin/apps/courses.csv')
print(df)

4. Ignore Header Record

Assume that you have a header with column names as the first row on the CSV file and you want to ignore this while reading, to do so use skiprows=1 and assign new column names as explained above.

read CSV without Header

# Ignore Header Record
columns = ['courses','course_fee','course_duration','course_discount']
df = pd.read_csv('/Users/admin/apps/courses.csv', header=None, 
     names=columns, skiprows=1)
print(df)

By not using the skiprows=1 param, it converts the header row with column names as data records.

Frequently Asked Questions (FAQ) on Reading CSV Without Headers in Pandas

How do I read a CSV file without headers in Pandas?

You can set the header parameter of the pd.read_csv() function as None to tell Pandas that the CSV file doesn’t have column headers. For example, df = pd.read_csv('file.csv', header=None)

What if I want to assign custom column names to the DataFrame when reading without headers?

You can provide a list of column names using the names parameter of the read_csv() function while reading a CSV file without a header. For example, custom_column_names = ['Column1', 'Column2', 'Column3']
df = pd.read_csv('file.csv', header=None, names=custom_column_names)

How can I specify the delimiter of the CSV file when reading without headers?

You can use the delimiter or sep parameter to specify the delimiter. The default is a comma (,), but you can change it to another character. For example, df = pd.read_csv('file.csv', header=None, delimiter='\t')

Are there any other parameters I should be aware of when reading CSV files without headers?

Depending on your data, you might want to explore additional parameters such as skiprows skipping a specific number of rows at the beginning of the file or dtype specifying data types for columns. For example, df = pd.read_csv('file.csv', header=None, skiprows=2, dtype={'Column1': int, 'Column2': float})

Conclusion

In this article, you have learned how to read a pandas CSV file with and without headers, If you don’t have a header use header=None. If you have a header then use skiprows=1 and use header=None.

Happy Learning !!

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