String Format
As we learned in the Python Variables chapter, we cannot combine strings and numbers like this:
Example
age = 36
txt = "My name is John, I am " + age
print(txt)
But we can combine strings and numbers by using f-strings or the format() method!
F-Strings
F-String was introduced in Python 3.6, and is now the preferred way of formatting strings.
To specify a string as an f-string, simply put an f in front of the string literal, and add curly brackets {} as placeholders for variables and other operations.
Example
Create an f-string:
age = 36
txt = f"My name is John, I am {age}"
print(txt)
Placeholders and Modifiers
A placeholder can contain variables, operations, functions, and modifiers to format the value.
Example
Add a placeholder for the price variable:
price = 59
txt = f"The price is {price} dollars"
print(txt)
A placeholder can include a modifier to format the value.
A modifier is included by adding a colon : followed by a legal formatting type, like .2f which means fixed point number with 2 decimals:
Example
Display the price with 2 decimals:
price = 59
txt = f"The price is {price:.2f} dollars"
print(txt)
A placeholder can contain Python code, like math operations:
Example
Perform a math operation in the placeholder, and return the result:
txt = f"The price is {20 * 59} dollars"
print(txt)