What Does {0} Mean In This Python String?

In Python, {0} within a string is a placeholder for a value that will be substituted into the string at runtime using the .format() method or, in more recent versions of Python, using f-strings. This is part of string formatting.

For example:

name = "John"
age = 30

# Using the .format() method
formatted_string = "My name is {0} and I am {1} years old".format(name, age)

# Using f-strings (Python 3.6 and later)
formatted_string = f"My name is {name} and I am {age} years old"

In both cases, {0} and {1} act as placeholders for the values of name and age, respectively. The .format() method or the f-string replaces these placeholders with the actual values, resulting in a formatted string. The numbering inside the curly braces specifies the position of the corresponding argument provided to .format() or the variable in the f-string.

You can use {0}, {1}, and so on to format strings when you want to insert variables or values into a string dynamically.