Exclude directories in a List Comprehension - python-3.x

Question

I want to get a list of all picture files in a directory, excluding certain subdirectories.
I have a List Comprehension I normally use to extract files, which works, but includes subdirectories I do not want.
This is on macOS and 'Photos Library.photoslibrary' is "package".The contents are normally hidden by the OS and the library appears to the user as a file, but to Unix this is just a normal directory which contains a massive number of files.
I have attempted to exclude the directory, as os.walk() describes, but my attempts all produce syntax errors.
the caller can modify the dirnames list in-place
(e.g., via del or slice assignment), and walk will only recurse into the
subdirectories whose names remain in dirnames
Is it possible to exclude within a List Comprehension
#!/usr/bin/python3
import os
pdir = "/Users/ian/Pictures"
def get_files(top, extension=".jpg"):
"""
For each directory in the directory tree rooted at top,
return all files which match extension.
"""
files = [os.path.join(dirname, filename)
for dirname, dirnames, filenames in os.walk(top)
# if 'Photos Library.photoslibrary' in dirnames:
# dirnames.remove('Photos Library.photoslibrary')
for filename in filenames
if filename.endswith(extension)
if 'Photos Library.photoslibrary' in dirnames:
dirnames.remove('Photos Library.photoslibrary')
]
return files
for file in get_files(pdir, (".JPG", ".JPEG", ".jpg", ".jpeg")):
print(file)

Answer 1

I couldn't get a List Comprehension to work, so I modified the code to a Generator Function, and make a List from the result.
The code below works.
def get_files(top, exclude=None, extension=".jpg"):
"""
For each directory in the directory tree rooted at top,
return all files which match extension.
exclude is an optional string or tuple/list of strings
to exclude named subdirectories.
"""
for dirname, dirnames, filenames in os.walk(top):
if(exclude is not None):
if(type(exclude) == str): # prevent Python treating str as sequence
if exclude in dirnames:
dirnames.remove(exclude)
else:
for excl in exclude:
if excl in dirnames:
dirnames.remove(excl)
for filename in filenames:
if filename.endswith(extension):
yield(os.path.join(dirname, filename))
for file in get_files(pdir, ('Photos Library.photoslibrary', 'iPhoto Library.photolibrary'), (".JPG", ".JPEG", ".jpg", ".jpeg")):
print(file)
The type test for exclude is inelegant, but Python polymorphism otherwise misinterprets strings,