I would like to get user input to refer to some list in my code. I think it's called namespace? So, what would I have to do to this code for me to print whatever the user inputs, supposing they input 'list1' or 'list2'?
list1 = ['cat', 'dog', 'juice']
list2 = ['skunk', 'bats', 'pogo stick']
x = raw_input('which list would you like me to print?')
I plan to have many such lists, so a series of if...then statements seems unruly.
In the cases I can think of right now it would probably be better to have a dictionary containing what you want the user to be able to reference, for example:
my_dict = {
'list1': ['cat', 'dog', 'juice']
'list2': ['skunk', 'bats', 'pogo stick']
}
key = raw_input('which list would you like me to print?')
print my_dict[key]
In fact, you can take advantage of the built-in globals(), like this:
list1 = ['cat', 'dog', 'juice']
list2 = ['skunk', 'bats', 'pogo stick']
x = raw_input()
print globals()[x]
The general idea of using a dict is good, but the best specific implementation is probably something like:
def pick_one(prompt, **kwds):
while True:
x = raw_input(prompt)
if x in kwds:
return kwds[x]
else:
print 'Please choose one of: ',
for k in sorted(kwds): print k,
print
To be used, e.g., as:
print pick_one('which list would you like me to print?',
list1 = ['cat', 'dog', 'juice']
list2 = ['skunk', 'bats', 'pogo stick'])
The point is that, when you're asking the user to select one among a limited number of possibilities, you'll always want to check that the choice was one of them (it is after all easy to mis-spell, etc), and, if not, prompt accurately (giving the list of available choices) and give the user another chance.
All sorts of refinements (have a maximum number of attempts, for example, after which you decide the user just can't type and pick one at random;-) are left as (not too hard but not too interesting either;-) exercises for the reader.