Question

I have a list of data in CSV file.

I am using loop to make them into fields… I need a code that look for a field in code that do not match this type of code “[A9]9AA9#9” Lets say “A” can be any letter and “9” can be any number. However [ ] and # symbol must be in the same location as in format.

def code():
    match= 0
    tree_file.readline() # skip first row
    for row in tree_file: 
        field=row.strip()
        field=field.split(",") # make Into fields
        code=(field[4])        
        if code != "[X9]9XX9#9":   #HERE SHOULD BE THE CODE
            match+=1        

Please can you leave some comment in code so I can understand them because I can’t understand how other solution that are available is relevant to my problem.

Answer 1

The regular expression you need is:

r'\[[A-Za-z][0-9]+\][0-9]+[A-Za-z]{2}[0-9]+#[0-9]+'

So the code can be like

import re

if re.search(r'\[[A-Za-z][0-9]+\][0-9]+[A-Za-z]{2}[0-9]+#[0-9]+', code) is None:
    match += 1  

Explanation

[A-Za-z] : matches any alphabet
[0-9]+ : matches one or more digits
[A-Za-z]{2} : matches two alphabets

Output

>>> import re
>>> s = "[X9]9XX9#9"
>>> re.search(r'\[[A-Za-z][0-9]+\][0-9]+[A-Za-z]{2}[0-9]+#[0-9]+', s) is None
False
>>> s = "ABCD"
>>> re.search(r'\[[A-Za-z][0-9]+\][0-9]+[A-Za-z]{2}[0-9]+#[0-9]+', s) is None
True
>>> s = "[A123]456BB8#789"
>>> re.search(r'\[[A-Za-z][0-9]+\][0-9]+[A-Za-z]{2}[0-9]+#[0-9]+', s) is None
False
>>>