Detailed description of Python string formatting

The string formatting operator (%) is very similar to the string formatting of the printf () function in C, and even the symbols used are the same, all with percent sign (%), and all printf () format operations are supported. The syntax is as follows:

Format_String% String_to_convert

Format_String is a format-tagged string, in the form "%cdoe"; String_to_convert is a string to be formatted, and if it is more than two, it needs to be enclosed in parentheses.

String formatting symbols

Formatting symbols	Description
%c	Convert to character (ASCII value, or string of one length)
%s	Convert to string, precedence string conversion with STR () function
%d	Turn into a signed decimal number
%u	Turn into unsigned decimal numbers
%o	Turn unsigned octal number
%x	(Unsigned) turns into unsigned hexadecimal numbers
%e	Turn into scientific counting method
%%	Output
%x	(Unsigned) to unsigned hexadecimal number, converted to 16 characters in uppercase, similar to%e (lowercase after conversion)

Example of string format output:

CharA = 65charB = 66print ("ASCII code 65 for:%c"% CharA) print ("ASCII code 66 stands for:%c"% charb) Num1 = 0xef3num2 = 0xab03print (' converted to decimal: %u and%u '% (NUM1, Num2)) Num3 = 1500000print (' Convert to scientific notation:%e '% Num3)

Output:

ASCII code 65 means: A

ASCII code 66 means: B

Converted to decimal: 3827 and 43779, respectively

Convert to scientific notation: 1.200000e+06

Formatting characters can also be used with auxiliary symbols, which is very handy.

Auxiliary symbols, as shown in the following table:

Auxiliary symbols	Description
*	Define width or decimal precision
-	Used for left justification
+	Show plus sign (+) in front of positive number
<sp>	Show spaces in front of positive numbers
#	Display 0 (0) in front of octal numbers, "0x" or "0X" before hexadecimal (depending on "x" or "X")
0	The displayed number is preceded by "0" instead of the default space
M.n	is the minimum total width displayed, and n is the number of digits after the decimal point

Note: The secondary symbol is to be between the percent sign (%) and the formatting symbol.

Examples of auxiliary symbols:

NUM1 = 108print ("% #X"% Num1) Num2 = 234.567890print ("%.2f"% Num2)

Output:

0x6c

234.57