Python format() Function

The format() function formats a specified value into a specified format.

Syntax

format(value, format)

format() Parameters

Python format() function parameters:

Parameter	Condition	Description
value	Required	A number or a string that can be converted into a floating point number
format_string	Required	The format you want to format the value into. Legal values: <: Left aligns the result (within the available space) >: Right aligns the result (within the available space) ^: Center aligns the result (within the available space) =: Places the sign to the left most position +: Use a plus sign to indicate if the result is positive or negative -: Use a minus sign for negative values only : Use a leading space for positive numbers ,: Use a comma as a thousand separator _: Use a underscore as a thousand separator b: Binary format c: Converts the value into the corresponding unicode character d: Decimal format e: Scientific format, with a lower case e E: Scientific format, with an upper case E f: Fix point number format F: Fix point number format, upper case g: General format G: General format (using a upper case E for scientific notations) o: Octal format x: Hex format, lower case X: Hex format, upper case n: Number format %: Percentage format

format() Return Value

Python format() function returns a value in the string representation of the desired format.

Examples

Example 1: number formatting using format() function

Example of decimal and binary formatting:

# decimal formatting
decimal_value = format(123, 'd')
print("Decimal Formatting:", decimal_value)

# binary formatting
binary_value = format(123, 'b')
print("Binary Formatting:", binary_value)

output

Decimal Formatting: 123
Binary Formatting: 1111011

Example 2: number formatting with sign using format() function

Let's use + and - format specifier:

positive_with_plus = format(123, '+') 
positive_with_minus = format(123, '-')

print("Positive with '+':", positive_with_plus) 
print("Positive with '-':", positive_with_minus)

output

Positive with '+': +123
Positive with '-': 123

Example 3: number formatting with precision using format() function

Precision allows us to define the number of digits to be shown after a decimal point.

For example, set precision to 2 for floating-point number:

precision_value = format(123.4567, '.2f')
print(precision_value)  # Output: 123.46

output

123.46

Example 4: number formatting with alignment and width

Alignment in formatting refers to the way a number is positioned or placed within the available space, determining where it starts and ends in relation to that space.

It controls how the number is visually presented within a designated area.

Alignment	Description
< left-align	Aligns the output string to the left
> right-align	Aligns the output string to the right
^ center-align	Aligns the output string to the center of the remaining space

For example, format number without specifying width:

no_width = format(123, 'd')
print("Without specified width:", no_width)

Without specified width: 123

For example, format number with a width of 10, right-aligned:

right_aligned = format(123, '>10d')
print("Right-aligned with width 10:", right_aligned)

Right-aligned with width 10:        123

For example, format number with a width of 10, left-aligned:

left_aligned = format(123, '<10d')
print("Left-aligned with width 10:", left_aligned)

Left-aligned with width 10: 123   

For example, format number with a width of 10, center-aligned:

center_aligned = format(123, '^10d')
print("Center-aligned with width 10:", center_aligned)

Center-aligned with width 10:    123