python中的简单C代码— switch语句

Question

I want to write this C++ code in Python:

cout<<"input number";
cin>>x;
switch(x)
{
 case '1':
   cout<<"my name is ali";
 case '2':
   cout<<"my name is hamza";
 default:
   cout<<"invalid input";
}
goto again:

I also checked the dictionary statement, but maybe I am coding it incorrectly.

Answer 1

This is one way to do it, there are no switch statements in python:

options = {"1":"my name is ali","2":"my name is hamza"} # map responses to keys

while True:
    x = raw_input("input number") # take user input, use `input()` for python 3
    if x in options: # if the key exists in the options dict
        print(options[x]) # print the appropriate response
        break # end the loop
    else:
        print("invalid input") # or else input is invalid, ask again

Answer 2

Python has no switch equivalent.

You can use if/else

if x == '1':
   print "my name is ali"
elif x == '2':
   print "my name is hamza"
else:
   print "invalid input"

If you are concerned that this may mean doing a lot of tests against x . You can often use a dict, with the keys being values of x . eg.

x_map = {"1": "my name is ali",
         "2": "my name is hamza"}

print x_map.get(x, "invalid input")

Answer 3

You can use dictionary like structure like this.

def my_switch(x):
    my_dict = {
            '1': 'my name is ali',
            '2': 'my name is hamza',
        }
    if x in my_dict.keys():
        return my_dict[x]
    else:
        return "invalid input"

Implementation of this function:

In [21]: my_switch('1')
Out[21]: 'my name is ali'

In [22]: my_switch('not a key')
Out[22]: 'invalid input'