Python-函数的参数小结
参数转化：
1 def fun(a, b, c): 2 print('a=', a) 3 print('b=', b) 4 print('c=', c) 5 6 fun(10, 20, 30) 7 lst = [10, 20, 30] 8 fun(*lst) #函数调用时，将列表中的每个元素都转换为位置实参传入 9 print('----------') 10 fun(a=100, b=200, c=300) 11 dic = {'a':100, 'b':200, 'c':300} 12 fun(**dic)
1 def fun(a, b=10): 2 print('a=', a) 3 print('b=', b) 4 5 def fun2(*args): 6 print(args) 7 def fun3(**args): 8 print(args) 9 10 fun2(10, 20, 30, 40) 11 fun3(a=11, b=22, c=33, d=44) 12 13 def fun4(a, b, c, d): 14 print('-----fun4------') 15 print('a=', a) 16 print('b=', b) 17 print('c=', c) 18 print('d=', d) 19 fun4(10, 20, 30, 40) 20 fun4(a=40, b=30, c=20, d=10) 21 fun4(10, 20, c=40, d=30) 22 # fun4(a=20, b=10, 30, 40) SyntaxError: positional argument follows keyword argument 23 24 '''如何要求cd必须为关键字传参？''' 25 def fun5(a, b, *, c, d): # *之后，必须是关键字传参 26 print('-----fun5------') 27 print('a=', a) 28 print('b=', b) 29 print('c=', c) 30 print('d=', d) 31 fun5(a=40, b=30, c=20, d=10) 32 fun5(10, 20, c=40, d=30) 33 34 '''函数定义时，形参的顺序问题''' 35 def fun7(a, b, *, c, d, **args): 36 pass 37 def fun6(*args1, **args2): 38 pass 39 def fun8(a, b=10, *args1, **args2): 40 pass
