Python insert variable in string with curly braces

In Python, you can use f-strings (formatted string literals) to insert variables into strings with curly braces {}. This is available in Python 3.6 and later.
Here's how you can do it:

name = "Alice"
age = 30
message = f"Hello, {name}. You are {age} years old."
print(message)

This is will be the output

Hello, Alice. You are 30 years old.

If you need to include curly braces {} in the string itself, you can double them {{ and }},

value = 42
message = f"The value is {{ {value} }}."
print(message)

Output look like this:

The value is { 42 }.

Alternatively, for versions before Python 3.6, you can use the .format() method:

name = "Alice"
age = 30
message = "Hello, {}. You are {} years old.".format(name, age)
print(message)

Or with named placeholders:

message = "Hello, {name}. You are {age} years old.".format(name="Alice", age=30)
print(message)