浅析python3字符串格式化format()函数的简单用法

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测试 format()函数
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def testFormat():
  # format()函数中有几个元素，前面格式化的字符串中就要有几个 \'{}\'
  # 位置
  s1 = \'a{}b{}c{}d{}\'.format(1, 2, 3, 4)
  # 索引，format()函数中的元素，从0开始
  s2 = \'a{0}b{1}c{3}d{2}\'.format(1, 2, 3, 4)
  # 索引可以重复使用
  s3 = \'a{0}b{1}c{0}d{1}\'.format(1, 2, 3, 4)
  print(\'-\' * 8)
  print(\'一般用法：\')
  print(s1)
  print(s2)
  print(s3)
  print(\'-\' * 8)
  # format()函数中元素个数，和前面的字符串中的\'{}\'个数不相同
  # 格式化字符串中的\'{}\'里面必须要有后面format()函数中元素的索引
  s4 = \'a{0}b{1}cd\'.format(1, 2, 3, 4)
  s5 = \'a{0}b{1}c{0}d{1}e{1}f{1}g{1}h{1}{4}{4}{4}{4}{5}{4}{4}{4}{4}\'.format(1, 2, 3, 4, \'*\', \'哈哈，这是第6个数，索引是5\')
  print(\'其他用法：\')
  print(s4)
  print(s5)
  print(\'-\' * 8)
  return
if __name__ == \'__main__\':
  testFormat()

 >>> li = [\'hoho\',]
 >>> \'my name is {} ,age {}\'.format(\'hoho\',)
 \'my name is hoho ,age \'
 >>> \'my name is {} ,age {}\'.format(,\'hoho\')
 \'my name is hoho ,age \'
 >>> \'my name is {} ,age {} {}\'.format(,\'hoho\')
 \'my name is hoho ,age hoho\'
 >>> \'my name is {} ,age {}\'.format(*li)
 \'my name is hoho ,age \'

 >>> hash = {\'name\':\'hoho\',\'age\':}
 >>> \'my name is {name},age is {age}\'.format(name=\'hoho\',age=)
 \'my name is hoho,age is \'
 >>> \'my name is {name},age is {age}\'.format(**hash)
 \'my name is hoho,age is 18\'

 >>> \'{:*>}\'.format() ##右对齐
 \'********\'
 >>> \'{:*<}\'.format() ##左对齐
 \'********\'
 >>> \'{:*^}\'.format() ##居中对齐
6 \'****10****\'

 >>> \'{:.f}\'.format(/)
 \'.\'
 >>> \'{:b}\'.format()  #二进制
 \'\'
 >>> \'{:o}\'.format()   #八进制
 \'\'
 >>> \'{:x}\'.format()   #进制
 \'a\'
 >>> \'{:,}\'.format() #千分位格式化
 \',,,\'

 >>> li
 [\'hoho\', ]
 >>> \'name is {[]} age is {[]}\'.format(li)
 \'name is hoho age is