CODEWITHSUNDEEP
pythonregexstringlistpython-2.7
CapnShanty
CapnShanty

Reputation: 89

I need to make sure that only certain characters are in a list?

I have this to get input and put it in a list:

def start():
    move_order=[raw_input("Enter your moves: ").split()]

And I only want the characters A, D, S, C, H (it's for a game >_>) to be allowed. I've tried using the regular expressions stuff:

if re.match('[ADSCH]+', [move_order]) is False:
    print "That's not a proper move!"
    return start()

...in different forms...

string_test=re.compile('[ADSCH]+')
    if string_test.match(move_order]) is False:
        print "That's not a proper move!"
        return start()

Aaaaand can't get it to work. I'm definitely doing something wrong within those code blocks, I tried to figure it out, but it's not working. Learning what I'm doing wrong would be nice, but the solution to my problem would teach me a lot more I feel like. I might not even need to use re, but it seemed to me that that was a space efficient way to accomplish what I want. My immediate problem I think is that I don't know how to get the re to use lists (unless (certainly) there's other glaring problems trained eyes can find).

I'll go ahead and ask since I'll probably screw this up too, but I also need to have it make sure that a C is never after an H... but a tiny hint for that would be acceptable because I like figuring things out.

Upvotes: 1

Views: 118

Answers (4)

user3636636
user3636636

Reputation: 2499

With such a small range you could just iterate the move_order and check if each element exists in the allowed moves

def start():
    move_order=[c for c in raw_input("Enter your moves: ")]
    moves = ['A','D','S','C','H']
    for c in move_order:
        if c not in moves:
            print "That's not a proper move!"
            return start()

Edit: Solution taking into account suggestions in comments

def start():
move_order=list(input("Enter your moves: "))
    while set(move_order) - set('ADSCH'):
        for x in set(move_order) - set('ADSCH'):
          move_order = [input("%s is not a vaild move, please enter another move" % x) if i==x else i for i in move_order]
    Print "Player ready" #Rest of program..

If I understand your question, i don't think split is doing what you think it is. It is not splitting each character of the string entered by the user into an array.

Upvotes: 0

TessellatingHeckler
TessellatingHeckler

Reputation: 29033

What are you doing with the characters afterwards? There might not be any need to even have this step. Design it so that when you're doing the actions for the moves, you don't/can't do any invalid ones.

def move_left():
    print "Moving left"

def move_down():
    print "moving down"

#...etc

def invalid_move():
    print "invalid move"

# This dictionary connects move command letters
# with the functions above that do the moving
move_funcs = {
    'A': move_left,
    'S': move_down,
    'D': move_right,
    'C': wtf_keyboard_layout,
    'H': do_H_thing
}

moves = raw_input("Enter your moves: ")
for move in moves.upper():

    # this gets the right function for the move, 
    # e.g. A gets move_left
    # but any character not there gets invalid_move
    move_func = move_funcs.get(move, invalid_move)
    move_func()

Upvotes: 0

LittleQ
LittleQ

Reputation: 1925

There're many ways to match 'ADSCH'
You can use raw_input().upper() to get rid of 'adsch'

use re: don't do split before 

def start():
    movement = raw_input("Enter your moves: ").upper()
    if re.match('^[ADSCH\s]*$', movement):
        # it's a legal input

use str.strip 

if movement.strip(' ADSCH') == '':
    # it's a legal input

use all with move_order list(works with string either):

def start():
    move_order=[raw_input("Enter your moves: ").upper().split()]
    if all((x in 'ADSCH' for x in move_order)):
        # it's a legal input

use any with move_order list(works with string either): 

if any((x not in 'ADSCH' for x in move_order)):
    # it's an illegal input

Upvotes: 1

user4914655
user4914655

Reputation:

I don't know python but you could do something like this:

for c in move_order:
if (c == 'A' or c == 'D' c == 'S' or c == 'C' or c == 'H'):
[do something with the character]

Upvotes: 0

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