How to format a floating number to fixed width in Python?

In Python, formatting a floating point number to a fixed width can be done using methods like Python's f-strings and the flexible format() method.

Float Formatting Methods

The two built-in float formatting methods are as follows ?

• f-strings: Convenient way to set decimal places, spacing and separators.

• str.format(): This method allows formatting types inside the placeholders to control how the values are displayed.

Using f-strings

We can format a floating-point number to a fixed width by using Python's f-strings. In the format specification {number:10.2f}, the 10 specifies the total width and .2f specifies 2 decimal places ?

Example

number = 123.4568
formatted = f"{number:10.2f}"
print(formatted)

The output of the above code is ?

   123.46

Using str.format() Method

The str.format() method is versatile for formatting strings in Python. Using this method, we can also control padding and alignment ?

Example

number = 123.4568
formatted = "{:10.2f}".format(number)
print(formatted)

The output of the above code is ?

   123.46

Padding and Alignment Options

We can control padding and alignment using the str.format() method with these alignment specifiers ?

• Right Align (>): Right-aligns the number within the specified width (default behavior).

• Left Align (<): Left-aligns the number within the specified width.

• Center Align (^): Centers the number with spaces on both sides.

• Zero Padding (0): Pads the number with zeros on the left side instead of spaces.

Example

number = 838.65

# Right align with spaces (default)
right_align = "{:>10}".format(number)
print('Right Align:', right_align)

# Left align with spaces
left_align = "{:<10}".format(number)
print('Left Align: ', left_align)

# Center align with spaces
center_align = "{:^10}".format(number)
print('Center Align:', center_align)

# Zero padding
zero_padding = "{:010.2f}".format(number)
print('Zero Padding:', zero_padding)

The output of the above code is ?

Right Align:      838.65
Left Align:  838.65    
Center Align:  838.65  
Zero Padding: 0000838.65

Format Specification Summary

Conclusion

Use f-strings for modern, readable formatting with f"{number:10.2f}" syntax. The str.format() method provides the same functionality with more explicit control over alignment and padding options.