Extracting 2 digits numbers from string-CodePudding

I have a file which contains string, from every string I need to append to my list every 2 digit number. Here's the file content: https://pastebin.com/N6gHRaVA

I need to iterate every string and check if string on index[i] and on index[i 1] is digit, if yes, append those digits to list and slice the string from those 2 digits number,

for example the string:

string = '7469NMPLWX8384RXXOORHKLYBTVVXKKSRWEITLOCWNHNOAQIXO' should work in this way:

Okay I have found digit 74, add 74 to my list and slice the string from 74 to the end
My string is now 69NMPLWX8384RXXOORHKLYBTVVXKKSRWEITLOCWNHNOAQIXO, I have found digit 69,add 69 to list and slice the string until I will find new 2-number digit. The problem is I always have error:

        if string[i].isdigit() and string[i 1].isdigit():
                               ~~~~~~^^^^^
IndexError: string index out of range

f = open("file.txt")
read = f.read().split()
f.close()
for string in read:
    l = list()
    i = 0
    print(string)
    while i<len(string):
        if string[i].isdigit() and string[i 1].isdigit():
            l.append(string[i]   string[i 1])
            string = string[i 2:]
            i = 0
        elif i==len(string)-1:
            break
        else:
            i =1
print(l)

My program stops at string in line 31, which is the string: 'REDOHGMDPOXKFMHUDDOMLDYFAFYDLMODDUHMFKXOPDMGHODER5'

I have no idea how to do this slice iteration, and please, don't use regex.

CodePudding user response：

You're going off the end of the string... Change:

 while i<len(string):

to:

 while i<len(string)-1:

And you should be fine.

If you were just looking at one character at a time, you could use your original while. The trick here is that you're always looking at a char and also "one ahead" of the char. So you have to shorten your check by one iteration to prevent going past the last char to check.

CodePudding user response：

You could use recursion. Here is what it would look like to deal with one of the strings.

Part of the code:

my_string = '7469NMPLWX8384RXXOORHKLYBTVVXKKSRWEITLOCWNHNOAQIXO'
result_list = []

def read_string(s):
    result = ""
    for i,j in enumerate(s):
        if i>0 and s[i-1].isdigit() and s[i].isdigit():
            result = s[i-1]   s[i]
            result_list.append(result)
            read_string(s[i 1:])
            break;
            
    return (result_list)        
     
# Call the read_string function
x = read_string(my_string) 
print(x)

OUTPUT:

['74', '69', '83', '84']

CodePudding user response：

Your loop condition i len(string). If string is not empty, this equals a positive intiger, which is evaluated as True. Hence, you created an endless loop, that meets it's end, when i gets greater then string length. Try this:

while i < len(string) -1:

EDITED:
Apparently, i didn't notice which string gave you the error. As you check for i 1th element of string, when we star checking the last character, reaching for the next one gives an obvious error. So, there should be -1 in the condition.