How to format numbers to strings in Python?

You can format numbers to strings in Python using several methods: the format() function, f-strings, and the % operator. Each approach allows you to control precision, width, and alignment.

Formatting Floating Point Numbers

Use the format() function to control decimal places and field width ?

nums = [0.555555555555, 1, 12.0542184, 5589.6654753]
for x in nums:
    print("{:10.4f}".format(x))

The output of the above code is ?

    0.5556
    1.0000
   12.0542
 5589.6655

The format {:10.4f} means: 10 characters total width with 4 decimal places.

Formatting Integers

Format integers using the d format specifier ?

nums = [5, 20, 500]
for x in nums:
    print("{:d}".format(x))

5
20
500

Adding Padding to Numbers

Specify field width to add padding and align numbers ?

nums = [5, 20, 500]
for x in nums:
    print("{:4d}".format(x))

   5
  20
 500

Using F-strings (Python 3.6+)

F-strings provide a more readable syntax for formatting ?

nums = [0.555555, 12.0542, 5589.6655]
for x in nums:
    print(f"{x:10.4f}")

    0.5556
   12.0542
 5589.6655

Comparison of Methods

Conclusion

Use f-strings for modern Python applications as they're more readable and performant. The format() function remains useful for compatibility with older Python versions.