I was creating a code to encode an input word.Letters in the input text is converted to a number and stored in a list.Here is the code is used,

z=input("input the word:")
x= z.strip()
y= -1
g=[ ]

while y<=len(x):
   y=y 1
   if x[y]==" ":
       g.insert(y,1000)
   if x[y]=="a":
     g.insert(y,1001)
   if x[y]=="b":
       g.insert(y,1002)    

and so on.....

But I was getting an error ,

Traceback (most recent call last):
 File "C:\Users\USER\Desktop\enc.py", line 13, in <module> 
if x[y]==" ": 
IndexError: string index out of range 

>>>

It would be grateful if anyone showed me what't wrong in the code.

CodePudding user response：

Look at your loop. You will run the loop even when y == len(x), and you bump the y first thing. So if the string is 3, you'll do the loop with y==4, when even x[3] is out of range. Just use a for loop. That's what they're for.

z=input("input the word:")
x= z.strip()
g=[ ]
for y in range(len(x)):
   if x[y]==" ":
       g.insert(y,1000)
   elif x[y]=="a":
       g.insert(y,1001)
   elif x[y]=="b":
       g.insert(y,1002)

I would probably use for y,c in enumerate(x):, but we'll leave that as an exercise for later.

So, even better:

g=[]
for c in x:
    if c==' ':
        g.append(1000)
    elif c=='a':
        g.append(1001)
    elif c=='b':
        g.append(1002)

An even better approach would be data-driven:

mapping = {
    ' ': 1000,
    'a': 1001,
    'b': 1002
}
g = [mapping[c] for c in x]

CodePudding user response：

The issue is that since Python is 0-indexed, you need to adjust the end range of your loop. len(y) is one number, but the last index of an interable is always len(y) - 1. If you adjust your loop accordingly, your issue should be fixed.

However, as another user commented, if you are set on using a while loop, be sure to incremented it after the code block; otherwise you will always skip the first element.

while y<=len(x) - 1:
   # do code
   y  = 1

or

while y < len(x):
   # do code
   y  = 1

Even better, use a for loop:

for i in range(len(x)):
   # do code

CodePudding user response：

You can do this with list comprehensions.

z = [(1000 if letter == " " else 1001 if letter == "a" else 1002 if letter == "b" else '') for letter in input("input the word: ")]
x = [y for y in z if y]