why is not python regex code not working?-CodePudding

I have pasted to code in which I have used regex library in python, while to work on regex I typecasted the x and y variable(in individual scripts) as string to work with regex functions but then also I'm unable to use that variable.

import re
field_value="CREDIT MEMO SHHAA00172362/AB2"
field_value=field_value.replace("CREDIT MEMO ","")
x=re.findall("/.*",field_value)
print(x)
if x:
  field_value=re.sub(str(x),"",field_value)
  print(field_value)

Why is the str type casting is not working on list x?

#Similarly:

import re
field_value='SICR-2205-11-0-00045-1'
y=re.findall('^[A-Z][A-Z][A-Z][A-Z]',field_value)
if y:
  print(y)
  x=re.split("-",field_value,1)
  print(x[0])
  print(x[2])
  if x[0] == str(y):
    print('123')

Why the str type casting is not working on list y?

CodePudding user response：

The method re.findall() always returns an array, even if it is empty or just contains one element.

So str(y) becomes the string "['SICR']".

If what you actually want to compare is the first match re.findall('^[A-Z][A-Z][A-Z][A-Z]',field_value) comes up with (in this case, "SICR") with x[0], then you actually want to do:

if x[0] == y[0]:
    print('123')

Since y[0] is the first match re.findall() found.