"Bala Ji" <bala...@gmail.com> wrote in message
news:11c1b4ef-07a3-4424-b356-9a9cf635f...@googlegroups.com...
>
>
> hello,
>
> thank you for your help
>
> i wrote this:
>
> x="nam1"
> y="F"
>
> names = [("nam1", "F", "Y"), ("nam2", "M", "N")]
> l = len(names)
> for i in range(0,l):
> print names[i][0]
> print names[i][1]
> if x == names[i][0] and y == names[i][1]:
> message = "right"
> else:
> message = "wrong"
>
> print message
>
>
> normally it must tell me "right" but it tells me "wrong"
>
> best
Your problem is that, after you find a valid name, you continue looping, and
then find an invalid name, so the message is over-written.
The usual way to terminate a loop without continuing to the next item is
with the 'break' statement.
Here are three variations of your code, each with an improvement over the
previous one -
1. This adds the break statement - it should do what you want -
l = len(names)
for i in range(0,l):
print names[i][0]
print names[i][1]
if x == names[i][0] and y == names[i][1]:
message = "right"
break
else:
message = "wrong"
2. This uses a feature of python which specifies an action to be taken only
if the loop continues to the end without interruption -
l = len(names)
for i in range(0,l):
print names[i][0]
print names[i][1]
if x == names[i][0] and y == names[i][1]:
message = "right"
break
else:
message = "wrong"
Note that the last two lines are indented to line up with the 'for '
statement. In the previous version, message is set to 'wrong' for every
iteration of the loop until a valid name is found. In this version, it is
only set to 'wrong' if no valid name is found.
3. This uses a feature of python which allows you to iterate over the
contents of a list directly -
for name in names:
print name[0]
print name[1]
if x == name[0] and y == name[1]:
message = "right"
break
else:
message = "wrong"
Hope this gives you some ideas.
Frank Millman
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