Python% formatted string

format string

• Python uses a string as a template
• The template contains a format character, reserving a location for the real value
• Use a tuple or dictionary to pass a value
• Between the template and the value, use% to represent the formatting operation

Example:

1) Tuple transfer value

Print ("I ' m%s, and  I ' m%d years old"  %  (' Tony ', 99))

2) Dictionary transfer value

Print ("I ' m% (name) s, and I ' m% (age) D years old"  %  {' name ': ' Tony ', ' Age ': 99})

When the dictionary is passed the value, we name the format string. So you can receive the value of the dictionary (key of the same name)

Format character meaning:

%s    string (displayed with str ())%r    string (display with repr ()%c    single character%b    binary integer%d    decimal integer%i    decimal integer%o    octal integer% x    hexadecimal integer%E    exponent (base write e)%E    exponent (base write e)%f floating-point number%f floating-point number    with the same%G    exponent (e) or floating-point number (based on display length)%G    exponent ( E) or floating-point number (depending on the display length)    the percent character "%"

Attention:

1) The difference between%s and%r is that%s does not have a ' ',%r with

Print ("%s"% ' abc ')    #   Abcprint ("%r"% ' abc ')    #   ' abc '

2) Percent does not understand?? 　　

3) In fact, in addition to naming , there are other options to control the string.

% [(name)] [flags] [width]. [Precision] TypeCode

• Where flags have +,--, 0, ' four kinds. Indicates that the string is pre-fill with these symbols
• Width indicates the output length of the string, the left complement
• Precision represents the output precision of the float type

Example:

Print ("%+10x"%)                #        +aprint ("%04d"% 5)                  #0005print ("%6.3f"% 2.3)               # 2.300# width and precision   You can also dynamically pass print ("%.4f"% 1.2)                 #1.2000print ("%.*f"% (4,1.2))            #1.2000

　

　　

Python% formatted string