Use Python to rewrite ABAP code
When you need to make mass changes to ABAP code, the SAPGui IDE isn’t of much help. Eclipse ADT is better, especially if you just want to rename stuff. But there are lots of changes which you won’t be able to automate there. Namely, changes that most be done hundreds of times and which cannot be done with a simple find and replace. In these cases you probably end up changing everything manually. But it doesn’t have to be that way.
Automate
Not long ago I was faced with one of those things. I needed to modernize some code in a very old program. So I decided to create a simple Python program to make these changes for me.
It is faster, safer and more fun.
Here’s the flowchart describing what I did:
Example
This is an old report using WRITE to output its results and we now want it to start writing them to the Application Log..
AS-IS
REPORT z_very_old.
START-OF-SELECTION.
WRITE / 'Starting...'.
LOOP AT itbl INTO wa.
WRITE: / 'Processing', wa-id, wa-description.
(...)
ENDLOOP.
WRITE 'Finised.'.
TO-BE
REPORT z_very_old.
START-OF-SELECTION.
logger->add_text( 'Starting...' ).
LOOP AT itbl INTO wa.
logger->add_text( 'Processing' && wa-id && wa-description ).
(...)
ENDLOOP.
logger->add_text( 'Finised.' ).
Python
As you can see, find and replace will not work here. And so I built a little Python program to do it for me. I’m not very versed in Python but it’s really simple. And fun. I iterated dozens of times, running it against small bits of code, slowly increasing its scope and functionalities until it was spitting out the desired ABAP code. This is what I ended up with:
#!/usr/bin/python
import re
import os
import sys
REGEX_WRITE = [
r'WRITE: / (.*?)\.',
r'WRITE / (.*?)\.',
r'WRITE: (.*?)\.',
r'WRITE (.*?)\.'
]
def load_file(filename: str) -> str:
with open(os.path.join(sys.path[0], filename), "r") as f:
return(f.read())
def remove_points_inside_strings(str: str) -> str:
""" To avoid making the regex expression unnecessarily complex """
str = str.replace("'Req.", "'Req")
str = str.replace(" repl.", " repl")
str = str.replace("Screen Rel.", "Screen Rel")
str = str.replace("WRITE: /.", "logger->add_text( ' ' ).")
str = str.replace("WRITE /.", "logger->add_text( ' ' ).")
return str
def convert_write_to_logger(str: str) -> str:
for r in REGEX_WRITE:
p = re.compile(r, re.S)
str = p.sub(r'logger->add_text( \1 ).', str)
return str
def concatenate_parts(str: str) -> str:
p = re.compile(r'logger->add_text\( ((?:.){0,300}?),((?:.){0,300}?) \)\.', re.S)
str2 = p.sub(
r'logger->add_text( \1 && \2 ).', str
)
if str2 != str:
str2 = concatenate_parts(str2)
return str2
if __name__ == "__main__":
str = load_file(sys.argv[1])
str = remove_points_inside_strings(str)
str = convert_write_to_logger(str)
str = concatenate_parts(str)
print(str)
Nothing fancy. I don’t care. It’s meant to be discarded. But it did in seconds what would have taken me an eternity.
If the code is scattered across several programs, includes, methods, etc, you can also use abapGit to export the whole code all at once and then run the Python program against it. It should work, even if you have to slightly adjust it.
Greetings from Abapinho.