Learn how to check if one Python string contains another using the contains () method. This case-sensitive instance method returns True or False based on …

May 31, 2024 - In this article, we will discuss different ways to check whether the given substring exists in the string or not. 1. Quick Examples of string contains

September 10, 2025 - Python counted how often the substring appears in the string and returned the answer. The text contains the substring four times. But what do these substrings look like? You can inspect all the substrings by splitting your text at default word borders and printing the words to your terminal using a for loop: ... >>> for word in file_content.split(): ... if "secret" in word: ... print(word) ... secret secret. secret, secretly · In this example, you use .split() to separate the text at whitespaces into strings, which Python packs into a list.

April 27, 2023 - The ‘in’ operator, find(), and index() methods are frequently used to check for a substring within a string by developers and we have attached the link to our tutorial on each above-mentioned string method so that you can read them too, but for this tutorial, we will be using the built-in function __contains__(). The Python string __contains__() function can be used with a string object, it takes a substring as an argument and returns True if the substring is present in the string.

For example, the following code checks if the string “hello” contains the substring “ell” using a regular expression: import re string = "hello" substring = "ell" pattern = r"ell" if re.search(pattern, string): print("The substring is ...

February 12, 2026 - A return value of 0 means "not found," so you could technically use .count() > 0 as a contains check. But that's doing extra work — it scans the entire string counting occurrences when you only need to know if there's at least one.

December 5, 2023 - In this example, we have a string ‘Hello, World!’ and we are checking if it contains the substring ‘World’. The in keyword in Python returns True if the substring exists in the string, and False otherwise.

Same as startswith, but tests the end of string. ... Returning a Series of booleans using only a literal pattern. >>> s1 = pd.Series(["Mouse", "dog", "house and parrot", "23", np.nan]) >>> s1.str.contains("og", regex=False) 0 False 1 True 2 False 3 False 4 False dtype: bool

December 20, 2025 - The in operator in Python checks if one string occurs within another. It evaluates to True if the substring is present in the main string, otherwise False. ... s = "Geeks welcome to the Geek Kingdom!" if "Geek" in s: print("Substring found!") else: print("Substring not found!") if "For" in s: print("Substring found!") else: print("Substring not found!") ... Substring found! Substring not found! ... The operator.contains() function checks for substring presence in a string programmatically.

December 20, 2022 - To check if a Python string contains the desired substring, you can use the "in" operator or the string.find() method.

For more detailed checks, like finding the position of the substring or avoiding exceptions, methods like .find(), .index(), and .contains() come into play. If you want to learn more about strings and string operations in Python, check out the Learn Python 3 course on Codecademy. Yes, the in operator is case-sensitive. For example, “Apple” in “Pineapple” returns False because of the capital “A”.

The easiest and most effective way to see if a string contains a substring is by using if ... in statements, which return True if the substring is detected. Alternatively, by using the find() function, it's possible to get the index that a substring starts at, or -1 if Python can't find the ...

May 25, 2020 - If you are coming to Python from Java, for instance, you might have used the contains method to check if some substring exists in another string. In Python, there are two ways to achieve this. The easiest way is via Python’s in operator. Let’s take a look at this example.

April 14, 2026 - What if the string could contain the substring more than once? Here is the syntax of the find method: We can use the two other arguments to set a starting and ending point in the string we are searching. Here is an example: The code above will return the start index of the second occurrence of the substring “sea.” · 100 Days of Code™: The Complete Python Pro Bootcamp Dr.

March 2, 2022 - Download You can download the full source code of this example here: Python String contains() method Tutorial

March 31, 2026 - Python’s text strings are Unicode. Substring operations are case-sensitive by default and implemented in C for speed. The most direct way to test if text appears inside a string is the in operator, which returns a Boolean using the string’s __contains__() implementation.

July 18, 2026 - What if you need to check whether one string contains another specifically at the beginning or the end of the string? You can use the string startswith method to check whether one string starts with another string: >>> whole = "I enjoy writing Python code." >>> whole.startswith("You ") False >>> whole.startswith("I ") True

November 7, 2025 - Output The string contains the substring ‘Python’.

March 15, 2024 - Time Complexity: The time complexity is O(n + m), n = length of the main string, and m is the number of words in the split string. This method splits the string and then iterates over the words to perform the search. In this example, the variable substring contains Python as a substring and will check whether it is present in main_string using the split method.