How to Split a String into a List in Python

Splitting a Python string into a list is a fundamental technique, especially useful when working with data structures or parsing input formats. Learning how to Python split string effectively is key for many tasks. This is because the vector in the input is often in the format of a string. Parsing a string and converting it into a list is comparatively more complex in languages like C++ and Java. Python, on the other hand, provides an easy way to convert the Python string into a string to list Python format by using the built-in methods. In this article, we will explore various techniques for Splitting string into a list in Python is a technique that is especially useful when working with data structures or parsing input formats. It’s a core aspect of string manipulation in Python.

Table of Contents:

• What is a String in Python?
• What is a List in Python?
• Different Ways to Split a String into a List in Python
  • Method 1: Use split() to Break a String by Delimiter in Python
  • Method 2: Split a String by Newline Using splitlines()
  • Method 3: Use re.split() to Split by Multiple Delimiters in Python
  • Method 4: Using partition() to Split a String into Three Parts
• Performance Tips for Splitting Large Strings in Python
• Which Python String Split Method Is Best for Your Use Case?
• Python Split String by Whitespace vs Delimiters
• How to Use split() with List Comprehension in Python?
• How to Split Strings in Python Without Losing Delimiters?
• Best Practices for String Splitting in Python
• Real-World Use Cases of Splitting Strings in Python
• Conclusion

What is a String in Python?

Python String is a primitive object data type in Python. It holds character and numeric values. It may even hold emojis or any undefined data. Strings are recognized by the quotes around the characters. You can declare a string using single quotes (‘’) as well as double quotes (“”).  Here are some examples of strings in Python. 

• “[INFO] 2025-04-08 14:30:00 – User logged in”
• “apple, banana, orange, grape”
• “Dr. John A. Smith”
• “https://intellipaat.com/blog/online-python-compiler/”
• “2025-04-08 14:30:00”

What is a List in Python?

Python lists are built-in data types that allow you to store mutable elements in a sequence. Mutable elements are those elements that can be modified after declaration. The elements in the List can be of different data types. There is no compulsion for the list to have homogeneous data types. Lists are recognized by square brackets around the elements. You can declare a list using square brackets ([]). Here are some examples of lists in Python.

• [“Line one”, “Line two”, “Line three”]
• [“apple”, “banana”, “orange”, “grape”]
• [1, 2, 3, 4, 5]
• [{“name”: “Lithin”}, {“name”: “Garima”}, {“name”: “Nithish”}]
• [“Age”, 25, “Active”, True]

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Different Ways to Split a String into a List in Python

Python offers many ways to split a string into a list and does it in a few lines of code. Let us understand each method and how to implement them with the help of a code.

Method 1: Use split() to Break a String by Delimiter in Python

The most basic way to Python split string into lists is using the split() function in Python. This method splits a string based on a delimiter and returns a string to list Python output of substrings. It is important that the string follow a consistent pattern for this method to work. The str.split() method operates directly on a Python string and also has two optional parameters, namely separator and maxsplit. 

• Separator: This determines where the string will split. This can also be referred to as a delimiter. By default, the value of the separator is whitespace. 

• Maxsplit: This parameter specifies the maximum number of splits to do. By default, the value of maxsplit is -1, which means that it splits across the entire string, and there are no limits to the splitting. This takes a separator parameter as well. If you do not mention the separator, it will, by default, take whitespace as the separator value.

Example: 

Output: 

Explanation: Here, we split the string text1 into a list of words using the split() method with the separator as a comma (,). The second string, text2, was split with a maxsplit parameter of 3.

Method 2: Split a String by Newline Using splitlines()

The splitlines() method is used to split the string based on the newline character (\n). You can also achieve this by using the Python split() method. Just set the value of the separator parameter as “\n.”

Example: 

Output: 

Explanation: Here, we assigned a multiline string to the variable text using triple quotes (‘‘‘ ’’’). Then we used the split() and the splitlines() methods in Python to split it based on new lines.

Method 3: Use re.split() to Split by Multiple Delimiters in Python

You can also use the Regular Expressions Module in Python to split the string into lists. This Python module has the re.split() method to do what split() in Python does. Whenever you need to Python split string on multiple characters or complex patterns, it is recommended that you use the regular expression (re) module. re allows you to split based on irregular separator patterns. This method also works like a charm when your input is not consistently formatted.  

If you are not familiar with the regular expressions module and how to use it, we recommend you first check out our Regular Expressions tutorial before moving forward.

Example: 

Let us consider a string “apple, banana;orange|grape / mango\tpineapple\npapaya.” This is inconsistently formatted. There is a comma after “apple” but a semicolon after “banana.” This string won’t split using the split() method.

Output:

Explanation: Here, we have an irregular string. We split it based on comma, semicolon, pipe, slash, tab, newline, and space in one go. 

Method 4: Using partition() to Split a String into Three Parts

The partition() method takes in a separator argument and then splits the string into two parts over this separator. The method returns a tuple containing three elements. The tuple contains (‘everything before a separator’, ‘the separator’, ‘everything after a separator’). You will have to convert the tuple into a list using the list() method. 

Example: 

Output:

Explanation: Here, we used the partition() method to split the email. It split it into three parts and returned the tuple. Then, we typecast the tuple to a list using list().

Performance Tips for Splitting Large Strings in Python

When you are working with very large Python string objects or massive datasets, optimizing how you split and process text can significantly improve performance. Here are some tips to keep in mind when working with large textual datasets:

• Use the Python split() method over re.split(), as the Python split() method is much faster and more memory efficient. If you do not have any complex delimiters, it is better to use split().
• Always avoid unnecessary loops. Iterating over large split lists multiple times can slow down your code. It is better to process them when you split them, if possible.

Which Python String Split Method Is Best for Your Use Case?

Python Split String by Whitespace vs Delimiters

How to Use split() with List Comprehension in Python

The Python split() function is one of the most commonly used functions for string manipulation in Python. The split() function, combined with list comprehensions, becomes a powerful tool to wield. List comprehension in Python is a way to create a new list by applying an expression to each item in an iterable, including an optional condition. 

This method can strip whitespace from elements, filter out unwanted values, and convert elements to different data. List comprehension paired with the Python split() method implements these techniques faster and in one line of code, making your string to list Python conversions efficient and optimized. Let us see how it is done using an example.

Example:

Output:

Explanation: Here, we have stripped the whitespace, converted the data type, and filtered out the elements based on a condition before printing the result in 1 line of code.

How to Split Strings in Python Without Losing Delimiters?

When you split a string into a list in Python, it usually splits on the delimiter (comma, period, colon, etc), and therefore, we lose the delimiter in the process. Although there are ways to preserve the delimiters when splitting a string, especially when you are working with parsing logs, data formats, or structured text, where delimiters matter. Python’s re.split() from the re module, along with regular expressions, gives you the flexibility to do that.
Let us look at an example using code and learn how it is done in Python.

Output:

Explanation: This keeps the delimiters (,, ;, and .) by wrapping the pattern in parentheses, which tells re.split() to include matches in the result.

Best Practices for String Splitting in Python

When performing string manipulation in Python to convert a Python string to a string to list Python format, following these best practices ensures efficient and readable code:

1. Choose the Right Method for Python split string:
   • For simple cases, like splitting by a single character or any whitespace, Python split() is your go-to. It’s fast and straightforward.
   • If you need to split based on complex patterns or multiple different characters, re.split() from Python’s re module is essential.
   • When you specifically need to split a multi-line Python string by newline characters, splitlines() is the most readable and direct option.
   • Use partition() or rpartition() when you only want to split a Python string into three distinct parts around the first or last occurrence of a delimiter, and you want to keep the delimiter itself in the result.
2. Always Specify the Delimiter with Python split() (Unless Whitespace is Intentional):
   • When using split(), explicitly state the delimiter (e.g., my_string.split(',')). This makes your code clearer and avoids unexpected behavior if the input data changes. If you intend to split by any sequence of whitespace (tabs, spaces, newlines), then calling split() without arguments is the correct approach.
3. Use maxsplit for Controlled Splitting:
   • If you only need to split the Python string a certain number of times, use the maxsplit argument in Python split() (e.g., my_string.split(':', 1)). This can improve performance on large strings and helps when parsing structured data where you expect a fixed number of fields.
4. Handle Empty Strings in Results:
   • Be aware that split() can produce empty strings in the resulting list if there are multiple delimiters together (e.g., "a,,b".split(',') gives ['a', '', 'b']). If these empty strings aren’t desired in your string to list Python conversion, you can filter them out using a list comprehension or filter(None, ...).
   • Example: [item for item in text.split(',') if item]
5. Consider Performance for Large Datasets:
   • While Python split() is highly optimized, for extremely large strings or performance-critical applications involving complex patterns, always consider benchmarking re.split() versus simpler string methods if performance becomes an issue. Generally, split() is faster for basic delimiters.
6. Clear and Descriptive Variable Names:
   • After you Python split string, assign the resulting list to variables with meaningful names. This greatly improves the readability of your code. For instance, parts = url.split('/') is better than x = url.split('/').

Real-World Use Cases of Splitting Strings in Python

Splitting the string is one of the basic functions used in real-world applications, especially in natural language processing tasks. Here we have listed some situations where the split-the-string function is particularly useful.

• One of the initial tasks in natural language processing (NLP) is tokenization. It is the process of breaking text down into tokens, which are then preprocessed for a task such as sentiment analysis, classification, or entity recognition.

Example: 

Output: 

Explanation: Here, the sentence is split into tokens.

• It is useful to separate text into individual words before analyzing the text. We clean it by transforming the words into lowercase, stripping extra white spaces, etc. This process is called text cleaning. It is a preprocessing step in NLP.

Example:

Output: 

Explanation: Here, we have applied the split() function and cleaned the text nlp process.

• Splitting a paragraph or file into sentences is beneficial to NLP applications like summarization or conversation in chatbots. This simplifies the data for processing and analysis.

Example: 

Output: 

Explanation: Here, we have split the paragraph into sentences for ease of use.

• You can split URLs into substrings with protocol, domain, path, and parameters. These can then be utilized to deal with routing, validating, or analyzing.

Example: 

Output: 

Explanation: Here, we have split the URL address. This way we can access the domain, categories, paths, etc. 

• Most log formats use symbols like commas, spaces, or pipes as delimiters, which can be used to split and extract useful data for analysis.

Example: 

Output: 

Explanation: Here, we have split the log into two parts, the message and the time stamp.

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Conclusion

Splitting strings into lists is an effective technique in Python that proves useful in a wide range of fields, from data analysis and text processing to file handling, highlighting its importance in string manipulation in Python. The functions, such as Python split(), splitlines(), and tools such as re.split(), help you Python split string with ease and fewer lines of code. These functions provide flexibility for both straightforward strings and complex strings with irregular formatting and patterns. By mastering these methods, you can write clean code. Whether you are developing data pipelines or constructing NLP models, understanding when and how to apply each method will help you write and present optimized Python code.

To take your skills to the next level, check out this Python training course and gain hands-on experience. Also, prepare for job interviews with Python interview questions prepared by industry experts.

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How to Split a String into a List in Python- FAQs