如何在另一個函數內調用函數？

Question

如果我有兩個功能，（一個在另一個裏面）;

def test1(): 
    def test2(): 
     print("test2") 

我怎麼叫test2？

Answer 1

你可以把它也以此方式：

def test1(): 
    text = "Foo is pretty" 
    print "Inside test1()" 
    def test2(): 
     print "Inside test2()" 
     print "test2() -> ", text 
    return test2 

test1()() # first way, prints "Foo is pretty" 

test2 = test1() # second way 
test2() # prints "Foo is pretty" 

讓我們來看看：

>>> Inside test1() 
>>> Inside test2() 
>>> test2() -> Foo is pretty 

>>> Inside test1() 
>>> Inside test2() 
>>> test2() -> Foo is pretty 

如果你不想叫test2()：

test1() # first way, prints "Inside test1()", but there's test2() as return value. 
>>> Inside test1() 
print test1() 
>>> <function test2 at 0x1202c80> 

讓我們更加努力：

def test1(): 
    print "Inside test1()" 
    def test2(): 
     print "Inside test2()" 
     def test3(): 
      print "Inside test3()" 
      return "Foo is pretty." 
     return test3 
    return test2 

print test1()()() # first way, prints the return string "Foo is pretty." 

test2 = test1() # second way 
test3 = test2() 
print test3() # prints "Foo is pretty." 

讓我們來看看：

>>> Inside test1() 
>>> Inside test2() 
>>> Inside test3() 
>>> Foo is pretty. 

>>> Inside test1() 
>>> Inside test2() 
>>> Inside test3() 
>>> Foo is pretty. 

Answer 2

def test1(): 
    def test2(): 
    print "Here!" 
    test2() #You need to call the function the usual way 

test1() #Prints "Here!" 

注意，test2功能不是test1外提供。例如，如果您稍後在代碼中嘗試致電test2()，則會發生錯誤。

Answer 3

您不能，因爲test2一旦test1()已返回就停止存在。要麼從外部函數返回它，要麼從那裏調用它。