python中使用選擇性參數

names=["1","2",["3","4"]]def print_lol(the_list,level):    for each_item in the_list:        if isinstance(each_item,list):            print_lol(each_item)        else:            for tab_stop in range(level):                print("\t",end="")            print(each_item)print_lol(names,2)

上面的結果：

1
2
Traceback (most recent call last):
File "D:/python/4.py", line 11, in <module>
print_lol(list23,0)
File "D:/python/4.py", line 6, in print_lol
print_lol(each_item)
TypeError: print_lol() takes exactly 2 arguments (1 given)

def print_lol(the_list,level):

這一句兩個參數是必要的，“level”是一個可選的參數

names=["1","2",["3","4"]]def print_lol(the_list,level=0):    for each_item in the_list:        if isinstance(each_item,list):            print_lol(each_item)        else:            for tab_stop in range(level):                print("\t",end="")            print(each_item)print_lol(names,2)

　結果是：

　　　　1
　　　　2
3
4

def print_lol(the_list,indent=False,level=0):    for each_item in the_list:        if isinstance(each_item,list):            print_lol(each_item,indent,level+1)        else:            if indent:                for tab_stop in range(level):                    print("\t",end="")            print(each_item)        names=["Bob","Tom",["jua","lun"],"pop"]print_lol(names)print("**********************")print_lol(names,True)print("**********************")print_lol(names,False,4)print("**********************")print_lol(names,True,4)

　　結果是：

 

 

BobTomjualunpop**********************BobTomjualunpop**********************BobTomjualunpop**********************BobTomjualunpop