Here is how to check if a string contains a substring in Python.

# Define a string
my_string = "Hello, world!"

# Check if the string contains the substring "world"
if "world" in my_string:
    print("The string contains the substring.")
else:
    print("The string does not contain the substring.") 

Copy & Run

---

Alternatively, you can use the find() method to check if a string contains a substring. This method returns the index of the first occurrence of the substring, or -1 if the substring is not found. Here's an example:

# Define a string
my_string = "Hello, world!"

# Find the index of the substring "world"
index = my_string.find("world")

# Check if the substring was found
if index != -1:
    print("The string contains the substring.")
else:
    print("The string does not contain the substring.")

This will also print 'The string contains the substring'.

Use the polars library
Use Selenium to browse a page
Load JSON data
Build a GUI with FreeSimpleGUI
Delete a directory
Delete a file
Create matplotlib graphs
Rename a file
Get today's date and convert to string
Create a text file and write text on it
Read a text file with Python
Scrape a Wikipedia page
Install dependencies
Flush the output of the print function
Prettyprint a JSON file
Create a dictionary with list comprehension
Select multiple columns in a Pandas dataframe
Profile a script
Reverse a string
Convert two lists into a dictionary
Convert an integer into a string
Generate random strings with upper case letters and digits
Extract extension from filename
Print to stderr in Python
Generate random integers between 0 and 9
Use a pythonic way to create a long multi-line string
Measure elapsed time in Python
Install specific package versions with pip
Read from stdin (standard input)
Get the class name of an instance
Check if a string is empty
Pad zeroes to a string
Delete an element from a dictionary
Check if a string is a float
Count the occurrences of an item in a list
Remove an element from a list by index
Use static methods
Remove a trailing newline
Print literal curly-brace characters in a string and also use .format on it
Exit/deactivate a virtualenv
Determine the type of an object
Limit floats to two decimal points
Know if an object has an attribute
Select an item from a list randomly
Read a file line-by-line into a list
Call a function of a module by using its name
Get the number of elements in a list
Print without a newline or space
Sort a list of dictionaries by a value of the dictionary
Remove a key from dictionary
Rename column names with Pandas
Lowercase a string
Upgrade all Python packages with pip
Get a substring of a string
Get the last element of a list
Parse a string to a float or integer
Convert a string into datetime format
Access environment variable values
Print coloured text on the terminal
Find current directory of a file
Change the size of figures drawn with Matplotlib
Manually raise an exception
Delete a file or folder
Split a list into evenly sized parts
Select rows from a DataFrame based on column values with Pandas
Install pip on Windows
Check if a given key already exists in a dictionary
Iterate over rows in a DataFrame for Pandas
Make function decorators and chain them together
Pass a variable by reference
Make a time delay
Convert bytes to a string
Copy a file
Concatenate two lists
Add new keys to a dictionary
Catch multiple exceptions in a single 'except' block
Check if a list is empty
Get the current time
Sort a dictionary by value
Use global variables in a function
List all files of a directory
Iterate over dictionaries using for loops
Find the index of an item in a list
Understand how slice notation works
Make a flat list out of a list of lists
Accesses the index in for loops
Safely create a nested directory
Merge two dictionaries in a single expression
Check whether a file exists without exceptions
Convert a dictionary into a list
Convert a list into a dictionary
Duplicate a file
Append text in a text file
Use for loops
Deploy a web app to Heroku
Schedule a Python script for execution at a specific time every day
Store Python passwords securely on Windows, Mac, and Linux
Do dictionary comprehension
Do list comprehension
Create a virtual environment
Create a new file
Merge two lists
Extract items from two different lists into one list
Check if a text file is empty
Randomly select an item from a list
Generate a random integer
Break a while loop
Create a pandas DataFrame from a dictionary
Create a pandas DataFrame from a list
Get the last item of a list
Delete a column from a pandas dataframe
Access a column of a pandas dataframe
Create a class
Make a webpage request
Get the first two characters of a string
Loop through two lists at the same time