Python string formatting

Format description

%d signed integer (decimal)

%i signed integer (decimal)

%o unsigned integer (octal)

%u unsigned integer (decimal)

%x unsigned integer (hexadecimal)

%x unsigned integer (16 uppercase characters)

%e floating-point numbers (scientific notation)

%E floating point number (scientific notation, E instead of e)

%f floating point number (with decimal point symbol)

%F

%g floating-point numbers (%e or%f depending on the size of the value)

%G floating-point number (similar to%G)

%c character and its ASCII code

%r processing objects with the Rper () method

The%s string uses the str () method to process the object, which is better for debug.

Percent percentile sign #就是输出一个%

%p pointer (memory address with hexadecimal print value)

%n the number of stored output characters into the next variable in the parameter list

The% format character can also be used in dictionaries, and the output can be formatted by using% (name) to refer to the elements in the dictionary.

The minus sign indicates that the number should be left-aligned, and "0" tells Python to fill the number with a leading 0, plus the number always displays its positive and negative (+,-) symbol, even if the number is positive.

You can specify the minimum field width, for example: "%5d"% 2. A period character can also be used to specify additional precision, such as "%.3d"% 3.

e.g.

# example: Numeric formatting

nyear = 2018

Nmonth = 8

Nday = 18

# formatted date%02d number to two-bit integer vacancy fill 0

print '%04d-%02d-%02d '% (nyear,nmonth,nday)

>> 2018-08-18# Output results

Fvalue = 8.123

print '%06.2f '%fvalue# reserved 2-bit decimal floating-point with a width of 6

>> 008.12# Output

print '%d '%10# Output Decimal

>> 10

print '%o '%10# output octal

>> 12

print '%02x '%10# output two-bit hex, letter lowercase blank complement 0

>> 0a

print '%04x '%10# output four-bit hex, letter capital Vacancy 0

>> 000A

print '%.2e '%1.2888# Output floating-point type with scientific notation reserved 2 decimal places

>> 1.29e+00

Formatting operator Auxiliary directives

Symbolic effect

* Define width or decimal point accuracy

-Used for left alignment

+ Show plus sign (+) in front of positive number

<sp> show spaces in front of positive numbers

# 0 (' 0 ') is displayed in front of the octal number, preceded by ' 0x ' or ' 0X ' in hexadecimal (depending on

Using ' x ' or ' x ')

0 The number shown is preceded by ' 0 ' instead of the default space

% ' percent ' output a single '% '

(VAR) mapping variable (dictionary parameter)

M.N m is the smallest total width displayed, and n is the number of digits after the decimal point (if available)

Basic methods of Use:

#coding =utf-8 ' can specify the alignment of the desired length of the string:<  (default) left >  right align ^  middle alignment =  (for numbers only) after the decimal point "print   ' 1:\t| {0:>10}, '. Format (' Wangyu ') print  ' 2:\t| {0:4.2f} '. Format (1.1415926) print  ' 3:\t| ', Format (1.1415926, ' <10.2f ') print  ' 4:\t| {0:<10},{1:<15} '. Format (' Wangyu ', 1.1415926) print  ' 5:\t| User id: {uid} last seen: {last_login} '. Format (uid= ' root ',last_login =  ' 5  mar 2008 07:20 ')    ' ' Format indicator can contain a presentation type to control the format. For example, a floating-point number can be formatted as a general format or represented by a power. ' B '  -  binary. The number is output as a base of 2. ' C '  -  characters. Converts an integer to the corresponding Unicode string before printing. ' d '  -  decimal integers. The number is output as a base of 10. ' O '  -  octal. The number is output as a base of 8. ' x '  -  16 binary. The number is output in 16, and the number of digits above 9 is in lowercase letters. The ' e '  -  power symbol. Print numbers in scientific notation. Use ' e ' to indicate power. ' G '  -  general format. The value is output in fixed-point format. When the number is particularly large, it is printed in a power form. ' n '  -  numbers. When the value is an integer and ' d ', the values are the same as the ' G ' when they are floating-point numbers. The difference is that it inserts a numeric delimiter according to the locale. '% '  -  percent. Multiply the value by 100 and then print in fixed-point (' F ') format, followed by a percent semicolon. " print " 6:\t| {0:b} '. Format (3) print  ' 7:\t|{0:c} '. Format (3) print  ' 8:\t| {0:d} '. Format (3) print  ' 9:\t| {0:o} '. Format (3) print  ' 10:\t| {0:x} '. Format (3) print  ' 11:\t| {0:e} '. Format (3.75) print  ' 12:\t| {0:g} '. Format (3.75) print  ' 13:\t| {0:n} '. Format (3.75)   #浮点数print   ' 14:\t| {0:n} '. Format (3)      #整数print   ' 15:\t| {0:%} '. Format (3.75)   #输入形式的控制formata  = int (Raw_input (' A: ')) B = int (Raw_input (' B: ')) print  ' 16:\t|%*.*f '  %  (a, b, 1.1415926)  print  ' 17:\t| {array[2]} '. Format (Array=range (Ten)) print  ' 18:\t| {attr.__class__} '. Format (attr=0) print  ' 19:\t| {digit:*^ 10.5f} '. Format (DIGIT=1.0/3)   ' "Class and type can define a __format__ () method to control how you format yourself. It will accept a format indicator as a parameter: "' Def __format__ (SELF,&NBSP;FORMAT_SPEC):  if isinstance (format_spec,  Unicode):   return unicode (str (self))  else:  return str (self)

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Python string formatting