Matching a string with Python RegEx negative lookahead

Question

I have a file with some content as wells as the two 'include' strings below:

some string1
some string2
...

include: "base_pricing_app_model_my_deployment_id.model.lkml"
include: "base_map_layers.model.lkml"
...
some string3
...

Substring "my_deployment_id" is a token I need to add to the second 'include' string so file content looks like that:

some string1
some string2
...

include: "base_pricing_app_model_my_deployment_id.model.lkml"
include: "base_map_layers_my_deployment_id.model.lkml"
...
some string3

I am running Python 3.5 and using its re library. Here is how I attempt to replace the second 'include' string:

with fileinput.input(files=(rfi), inplace=True) as cmodf:
for line in cmodf:
    match_no_dep_id = re.sub('^include:\s\"(?!my_deployment_id).*[.]model[.]lkml\"$', line.split('.')[0] + '_' + 'my_deployment_id' + 'model.lkml' + '"',  line)
    print(match_no_dep_id, end='')

However, both 'include' entries get modified and I end up with the following content:

some string1
some string2

include: "base_pricing_app_model_my_deployment_id_my_deployment_id.model.lkml"
include: "base_map_layers_my_deployment_id.model.lkml"

some string3
...

So my negative lookahead regexp matches both strings, including the one which already contains the token I am negating.

I am not sure what I am missing here. Please help.

Thank you!

Ryan Tam · Accepted Answer · 2018-05-16 22:11:44Z

I believe what you want is ^include:\s\".*(?<!my_deployment_id)\.model\.lkml\"$

With yours (i.e. ^include:\s\"(?!my_deployment_id).*[.]model[.]lkml\"$), you are filtering out entries like these include: "include: "my_deployment_id.base_map_layers.model.lkml" (Notice my_deployment_id comes before and not right before .model.lkml)

In [1]: string1 = 'include: "base_pricing_app_model_my_deployment_id.model.lkml"'
   ...: string2 = 'include: "base_map_layers.model.lkml"'
   ...: 
   ...: import re
   ...: 
   ...: 
   ...: def clean_include(include: str) -> str:
   ...:     return re.sub(
   ...:         '^include:\s\".*(?<!my_deployment_id)\.model\.lkml\"$',
   ...:         include.split('.')[0] + '_' + 'my_deployment_id' + '.model.lkml' + '"',
   ...:         include,
   ...:     )
   ...: 
   ...: 
   ...: print(clean_include(string1))
   ...: print(clean_include(string2))
   ...: 
   ...: 
include: "base_pricing_app_model_my_deployment_id.model.lkml"
include: "base_map_layers_my_deployment_id.model.lkml"

Collectives™ on Stack Overflow

Matching a string with Python RegEx negative lookahead

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related