Format ()() Function in Python

This updated guide examines Format ()() Function in Python and organizes the essential facts, background, and practical takeaways in clear American English.

Syntax of format () function in Python:

format(value[, format_spec])

Parameters of format function ()

The format () function has 2 parameters:

• value: value to be formatted.
• format_spec: the format you want for the value.

Format sets:

TypeDescribe Align the result = Set a positive sign (+) or negative (-) in the left margin d Integer format c Unicode character corresponding b Binary format o Definition octal format x Hexadecimal format (lower case) X Hexadecimal format (uppercase) n Decimal format e Hat notation. (lowercase e) E Hat notation. (uppercase E) f Real number floating point format (Default: 6) F Same as 'f', but displays uppercase letters, for example 'inf' is 'INF' and 'nan' is 'NAN' g General format. Round numbers to p significant digits. (Default: 6) G Same as 'g', switch to 'E' if the number is too large. % Percentage.

The order format is as follows:

[[fill]align][sign][#][0][width][,][.precision][type]

Inside:

• fill: is any character
• align: alignment, "<" | ">" | "=" | "^"
• sign: sign, "+" | "-" | ""
• width: string length, is an integer
• precision: precision, is an integer
• type: format type, "b" | "c" | "d" | "e" | "E" | "f" | "F" | "g" | "G" | "n" | "o" | "s" | "x" | "X" | "%"

Value returned from format ()

The format () method returns the formatted result of a given value determined by a specific format.

Example 1: Number format with format ()

# d, f và b là lo?i ??nh d?ng # s? nguyên print(format(123, "d")) # s? th?p phân # vi?t b?i TipsMake.com print(format(123.4567898, "f")) # nh? phân print(format(12, "b"))

Run the program, the result is:

123 123.456790 1100

Example 2: Number format with alignment

# s? nguyên print(format(1234, "*>+7,d")) # s? th?p phân print(format(123.4567, "^-09.3f"))

Output returns:

*+1,234 0123.4570

Here, when formatting the integer 1234, we specify the format including*<+7,d. Why is that? Details are as follows:

• *Character fill, fill in the blank after formatting.
• >Right alignment option, so the output string is on the right.
• +Option to force the output to be signed (with the sign on the left).
• 7Optionally specify the length of the result, forcing the return number to have a minimum length of 7 characters, other spaces will be filled with fill characters.
• ,Thousands operators, commas will be placed between thousands of digits and the remaining digits.
• doption to specify the result is an integer.

When formatting floating point numbers 123.4567, we specify the format including^-09.3f, details are as follows:

• ^option to align the center position, so the output sequence will be in the middle of the specified space.
• -Option to force the output to display a negative sign.
• 0Characters added to the spaces after formatting.
• 9Optionally specify the length of the result, forcing the return number to have a minimum length of 9 characters (including decimal points, commas, and a negative sign).
• .3precision operator, determine the precision, round to the third digit after the decimal point.
• foption to specify the result to return is a floating-point number.

Example 3: Use format () by overwriting __format __ ()

# ph??ng th?c __format __ () tùy ch?nh class Person: def __format__(self, format): if(format == 'age'): return '23' return 'None' print(format(Person(), "age"))

Run the program, the result is:

23

Here, we override the __format __ () method of the Person class, and the format () method inside of runningPerson().__format__("age")to return23.

See also: Built-in Python functions