string formatting

string formatting

1. Percent sign

Common formats:

 1 tpl = "i am %s" % "alex"
 2  
 3 tpl = "i am %s age %d" % ("alex", 18)
 4  
 5 tpl = "i am %(name)s age %(age)d" % {"name": "alex", "age": 18}
 6  
 7 tpl = "percent %.2f" % 99.97623
 8  
 9 tpl = "i am %(pp).2f" % {"pp": 123.425556, }
10  
11 tpl = "i am %.2f %%" % {"pp": 123.425556, }

%s # can take any value

%d # can take an integer value

%f #Print floating point numbers, such as %.2f means take two decimal places

%. #Intercept length, such as %.4s means to intercept a 4-digit string

%% # percent sign

%(pp) # Take the K value in the dictionary

 

PS：

print('root','x','0','qq',sep=':') # can be output

 

Second, format formatting

Common formats:

tpl = "i am {}, age {}, {}".format("seven", 18, 'alex')
  
tpl = "i am {}, age {}, {}".format(*["seven", 18, 'alex'])
  
tpl = "i am {0}, age {1}, really {0}".format("seven", 18)
  
tpl = "i am {0}, age {1}, really {0}".format(*["seven", 18])
  
tpl = "i am {name}, age {age}, really {name}".format(name="seven", age=18)
  
tpl = "i am {name}, age {age}, really {name}".format(**{"name": "seven", "age": 18})
  
tpl = "i am {0[0]}, age {0[1]}, really {0[2]}".format([1, 2, 3], [11, 22, 33])
  
tpl = "i am {:s}, age {:d}, money {:f}".format("seven", 18, 88888.1)
  
tpl = "i am {:s}, age {:d}".format(*["seven", 18])
  
tpl = "i am {name:s}, age {age:d}".format(name="seven", age=18)
  
tpl = "i am {name:s}, age {age:d}".format(**{"name": "seven", "age": 18})
 
tpl = "numbers: {:b},{:o},{:d},{:x},{:X}, {:%}".format(15, 15, 15, 15, 15, 15.87623, 2)
 
tpl = "numbers: {:b},{:o},{:d},{:x},{:X}, {:%}".format(15, 15, 15, 15, 15, 15.87623, 2)
 
tpl = "numbers: {0:b},{0:o},{0:d},{0:x},{0:X}, {0:%}".format(15)
 
tpl = " numbers: {num:b},{num:o},{num:d},{num:x},{num:X}, {num:%} " .format(num=15)

 

{0} # Take the value of the 0th bit in the parameter

* #The prefix symbol required to take the value in the list

** #The prefix symbol required to take the value in the dictionary

:s # can take any value

:f #Print floating point numbers, such as %.2f means take two decimal places

:b #binary

:o #octal

:d #integer/decimal

:x #hex/lowercase

:X #hex/uppercase

:% #Percentage, last 6 digits by default