Formatting Output

When displaying output in Python, you may want to format it so its easier to read. Python provides several ways to format strings for output. Here are some common methods:

Using f-strings (Python 3.6+)

F-strings provide a way to embed expressions inside string literals, using curly braces {}. They are prefixed with the letter f.

# Example of f-string formatting
name = "Alice"
age = 30
print(f"Name: {name}, Age: {age}")

This will output:

Name: Alice, Age: 30

You can use the variable names directly inside the curly braces, and Python will replace them with their values. However this only works if you prefix the string with f as shown above.

Using the format() method

The format() method allows you to format strings by placing curly braces {} as placeholders within the string and then calling the format() method on the string.

# Example of format() method
name = "Bob"
age = 25
print("Name: {}, Age: {}".format(name, age))

Here the first {} is replaced by the first argument given to the format method (name) and the second {} is replaced by the second argument given to the format method (age).

This will output:

Name: Bob, Age: 25

Using the % operator

The % operator can also be used for string formatting. It uses format specifiers to indicate where to insert values.

# Example of % operator formatting
name = "Charlie"
age = 28
print("Name: %s, Age: %d" % (name, age))

Here the placeholders are %s and %d . The values to be inserted are provided in parentheses after the % operator. They are inserted in the order they appear.

This will output:

Name: Charlie, Age: 28

You may be wondering why we use the letters s and d in the placeholders.

• %s is used for strings.
• %d is used for integers (decimal numbers).
• %f is used for floating-point numbers.

This means you can format different types of data appropriately. You must make sure to use the correct format specifier for the type of data you are inserting.

Summary

We have covered three common methods for formatting output in Python: f-strings, the format() method, and the % operator.

Try each one out to see which you prefer!