How To Specify A Delimiter In Python

Delimiters play an essential role in organizing your data, especially when working with text files or strings.

They help separate data values, making it easier to read and process the information. In Python, delimiters are commonly used in the popular function str.split(), as well as in file handling operations. In this tutorial, we will learn how to specify a delimiter in Python.

Step 1: Using split() function

The str.split() function is used to split a string into a list based on the specified delimiter. If no delimiter is specified, it uses whitespace as the default delimiter.

Let’s take a look at some examples of how to use the split() function with different delimiters. Here’s an example using whitespace:

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text = "Python is a very powerful programming language"
result = text.split()
print(result)

Output:

['Python', 'is', 'a', 'very', 'powerful', 'programming', 'language']

In this example, we use a comma as the delimiter:

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text = "Python,Java,C++,C#,Ruby"
result = text.split(",")
print(result)

Output:

['Python', 'Java', 'C++', 'C#', 'Ruby']

Step 2: Using the csv.reader() to specify delimiter in files

When working with files, you might need to use specific delimiters to read data from CSV files. The csv.reader() from the csv module allows specifying a delimiter when processing CSV files.

Consider the following example.csv file:

Python,Java,C++,C#,Ruby
2020,2010,1985,2000,1995

This example reads data from the example.csv file using a comma as the delimiter.

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import csv
 
with open('example.csv', mode='r') as file:
    reader = csv.reader(file, delimiter=',')
 
    for row in reader:
        print(row)

Output:

['Python', 'Java', 'C++', 'C#', 'Ruby']
['2020', '2010', '1985', '2000', '1995']

Step 3: Using string formatting to specify delimiter when concatenating values

When concatenating values with a delimiter, you can use string formatting methods such as str.format() or f-strings (Python 3.6+) to achieve the desired result.

Here’s an example using the str.format() method:

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languages = ["Python", "Java", "C++", "C#", "Ruby"]
delimiter = ","
result = delimiter.join(languages)
print(result)

Output:

Python,Java,C++,C#,Ruby

Using an f-string, we can achieve the same result:

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languages = ["Python", "Java", "C++", "C#", "Ruby"]
delimiter = ","
result = f"{delimiter}".join(languages)
print(result)

Output:

Python,Java,C++,C#,Ruby

Full code

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import csv
 
with open('example.csv', mode='r') as file:
    reader = csv.reader(file, delimiter=',')
 
    for row in reader:
        print(row)
 
languages = ["Python", "Java", "C++", "C#", "Ruby"]
delimiter = ","
result = delimiter.join(languages)
print(result)
 
languages = ["Python", "Java", "C++", "C#", "Ruby"]
delimiter = ","
result = f"{delimiter}".join(languages)
print(result)

Conclusion

In this tutorial, we explored how to specify a delimiter in Python using various techniques such as the str.split() function, the csv.reader(), and string formatting methods. Using these methods, you can easily work with data using custom delimiters and ensure proper organization and processing of your data.