在Python中是否有goto或任何等价的东西能够跳转到特定的代码行?


当前回答

不,有另一种方法来实现goto语句

class id:
     def data1(self):
        name=[]
        age=[]   
        n=1
        while n>0:
            print("1. for enter data")
            print("2. update list")
            print("3. show data")
            print("choose what you want to do ?")
            ch=int(input("enter your choice"))
            if ch==1:    
                n=int(input("how many elemet you want to enter="))
                for i in range(n):
                    name.append(input("NAME "))
                    age.append(int(input("age "))) 
            elif ch==2:
                name.append(input("NAME "))
                age.append(int(input("age ")))
            elif ch==3:
                try:
                    if name==None:
                        print("empty list")
                    else:
                        print("name \t age")
                        for i in range(n):
                            print(name[i]," \t ",age[i])
                        break
                except:
                    print("list is empty")
            print("do want to continue y or n")
            ch1=input()
            if ch1=="y":
                n=n+1
            else:
                print("name \t age")
                for i in range(n):
                    print(name[i]," \t ",age[i])
                n=-1
p1=id()
p1.data1()  

其他回答

不,Python不支持标签和goto。它是一种高度结构化的编程语言。

不,有另一种方法来实现goto语句

class id:
     def data1(self):
        name=[]
        age=[]   
        n=1
        while n>0:
            print("1. for enter data")
            print("2. update list")
            print("3. show data")
            print("choose what you want to do ?")
            ch=int(input("enter your choice"))
            if ch==1:    
                n=int(input("how many elemet you want to enter="))
                for i in range(n):
                    name.append(input("NAME "))
                    age.append(int(input("age "))) 
            elif ch==2:
                name.append(input("NAME "))
                age.append(int(input("age ")))
            elif ch==3:
                try:
                    if name==None:
                        print("empty list")
                    else:
                        print("name \t age")
                        for i in range(n):
                            print(name[i]," \t ",age[i])
                        break
                except:
                    print("list is empty")
            print("do want to continue y or n")
            ch1=input()
            if ch1=="y":
                n=n+1
            else:
                print("name \t age")
                for i in range(n):
                    print(name[i]," \t ",age[i])
                n=-1
p1=id()
p1.data1()  

你可以使用python中的嵌套方法来实现

def func1():
    print("inside func1")
    def inline():
        print("im inside")
    
    inline()
    
func1()

Python 2和3

pip3 install goto-statement

在Python 2.6到3.6和PyPy上测试。

链接:转向语句


foo.py

from goto import with_goto

@with_goto
def bar():

    label .bar_begin

    ...

    goto .bar_begin

Python为您提供了使用第一类函数可以用goto完成的一些事情的能力。例如:

void somefunc(int a)
{
    if (a == 1)
        goto label1;
    if (a == 2)
        goto label2;

    label1:
        ...
    label2:
        ...
}

在Python中可以这样做:

def func1():
    ...

def func2():
    ...

funcmap = {1 : func1, 2 : func2}

def somefunc(a):
    funcmap[a]()  #Ugly!  But it works.

当然,这并不是代替goto的最佳方式。但是如果你不知道你想用去做什么,就很难给出具体的建议。

@ascobol:

最好的方法是将其包含在函数中或使用异常。对于函数:

def loopfunc():
    while 1:
        while 1:
            if condition:
                return

对于例外情况:

try:
    while 1:
        while 1:
            raise BreakoutException #Not a real exception, invent your own
except BreakoutException:
    pass

如果您来自另一种编程语言,使用异常来做这样的事情可能会感觉有点尴尬。但我认为,如果您不喜欢使用异常,Python并不适合您。: -)