s1 = input("enter 1st string: ")
s2 = input("enter 2nd string: ")
if s2 in s1:
print("found")
else:
print("not found")
simply i want to say if i give some input to s1 and not give anything as input to s2 and press enter, Output of this code print "found" which is wrong because blank is not in my string s1, So why it is happening? and how to correct it?
Every string contains the empty string so '' in 'anything' is always True.
Every string always contains the empty string.
i = 'anything'.count('')
print(i)
# 9
As you can see, between every letter and before and after the string, there is 'the empty string'.
In your example, you can ensure that a non-empty string is entered like so:
while(True):
s1 = input("enter 1st string: ")
if s1 != '':
break
while(True):
s2 = input("enter 2nd string: ")
if s2 != '':
break
if s2 in s1:
print("found")
else:
print("not found")
Also note:
s = '' + 'a' + '' + 'n'+ '' + 'y' + '' + 't' + '' + 'h' + '' + 'i' + '' + 'n' + '' + 'g' + ''
print(s == 'anything')
# True
print(s.count('')
# 9
Adding more empty strings does not have any effect.
s += ''
print(s.count('')
# 9
