如何检查输入是否在python中的列表中？

Question

I want to be able to enter a value and check if it is in a list and if it is then in the list run a the rest of the program wanted.

a=input('enter value')
b=(1,2,3,4)
c=(5,6,7,8,9)
if a is in b:
   print 'enter in code thats wanted'

Answer 1

You've written it yourself almost correctly, just instead of -

if a is in b:

it should be -

if a in b:

Answer 2

condition should be

if a in b:
    print 'enter in code thats wanted'

Answer 3

• in operator: The 'in' operator is used to check if a value exists in a sequence or not. Evaluates to true if it finds a variable in the specified sequence and false otherwise.

• 'is' operator: Evaluates to true if the variables on either side of the operator point to the same object and false otherwise.

hence:

if a in b:
    print 'enter in the code that\'s wanted'