python 星号(*)的多种用途

def func3(a, b, c):
  print("param a is {}, param b is {}, param c is {}".format(a, b, c))


if __name__ == '__main__':
  arr1 = [1, 2, 3]
  print(arr1, sep='\t') # [1, 2, 3]\t 正常输出
  print(*arr1, sep='\t') # 1\t2\t3 每个数字中间以\t分割

  arr2 = [[1, 2, 3], [3, 4, 5], [5, 6, 7]]
  print(list(zip(*arr2))) # [(1, 3, 5), (2, 4, 6), (3, 5, 7)] 二维数组的行转列

  dictionary = {'a': 1, 'b': 2, 'c': 3}
  print(dictionary, sep='\t') # {'a': 1, 'b': 2, 'c': 3}\t 正常输出
  print(*dictionary, sep='\t') # a\tb\tc\t 每个字母中间以\t分割


  print(func3(**dictionary)) # param a is 1, param b is 2, param c is 3

def func1(*args):
  print("type", type(args)) # type <class 'tuple'>
  print("all arguments: ", args) # all arguments: (1, 2, 3)
  print("second argument: ", args[1]) # second argument: 2


def func2(**kw):
  print("type", type(kw)) # type <class 'dict'>
  print("all arguments: ", kw) # all arguments: {'a': 1, 'b': 2, 'c': 3}
  print("second argument: ", kw['a']) # second argument: 1


if __name__ == '__main__':
  a, b, c = 1, 2, 3

  func1(a, b, c)
  func2(a=a, b=b, c=c)