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Some things that should be easy are ridiculously hard in Python. Regexes for one have a horrible API story. Another one is the import system which I view as a t

Some things that should be easy are ridiculously hard in Python. Regexes for one have a horrible API story. Another one is the import system which I view as a totally broken effort to heal self-inflicted complexity with more complexity. Here is the code I came up when presented with the task to import a module when its name is given: def module_from_path( ctx, name, path ): ### thx to https://stackoverflow.com/a/50395128/7568091 ### ### thx to https://stackoverflow.com/a/67692/7568091 ### import importlib import importlib.util spec = importlib.util.spec_from_file_location( name, path ) module = importlib.util.module_from_spec( spec ) sys.modules[ spec.name ] = module spec.loader.exec_module( module ) return importlib.import_module( name ) Details may change any time without notice. The complexity here is a consequence of Python's design decision to treat module names as identifiers, not as quoted strings. The import system is full of such poor choices (dot/relative imports, `__init__.py`, `*.pyc` / `*.pyo` files littering one's source directories, and so on)

tails4e 4y ago
Agree on regex. I started in perl many years ago and loved how integrated regexes were. Was appalled that was was a simple one liner in perl turned into multiple lines in python for every regex. Making a powerful tool easy to use means it will be used more. It would be nice if that flaw could be fixed, as I like coding in python in general
- deleted 4y ago
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- eesmith 4y ago
  Here' an ancient hack that showed how that might look like - http://dalkescientific.com/Python/python4ply-tutorial.html#matching http://dalkescientific.com/Python/python4ply-tutorial.html#m... . count = 0 t1 = time.time() for line in open("nucleosome.pdb"): if line =~ m/(ATOM |HETATM)/: count += 1 print count, "atoms in", time.time()-t1, "seconds" It used it own PLY-based parser to generate the Python AST. None of it would work now. :)
  - eesmith 4y ago
    I realize now how much of a hack it is. The portion 'm/(ATOM |HETATM)/' could be part of valid Python expression, as: >>> ATOM = HETATM = 1 >>> m = 2 >>> m/(ATOM |HETATM)/1 2.0 so either m// is enabled only after =~, or there has to be some way to recognize the lexically correct match term -- something more powerful than the "m/[^/]*/[a-z]*" used here.
dvdkon 4y ago
I have to say I really like Python's module system. Modules as objects, scoped import by default and filesystem-backed module resolution (+sys.path) are all good choices in my opinion. Cosmetic warts like __pycache__ are unfortunate, but not deal-breakers.

tails4e 4y ago

Agree on regex. I started in perl many years ago and loved how integrated regexes were. Was appalled that was was a simple one liner in perl turned into multiple lines in python for every regex. Making a powerful tool easy to use means it will be used more. It would be nice if that flaw could be fixed, as I like coding in python in general

deleted 4y ago
[deleted]
eesmith 4y ago
Here' an ancient hack that showed how that might look like - http://dalkescientific.com/Python/python4ply-tutorial.html#matching http://dalkescientific.com/Python/python4ply-tutorial.html#m... . count = 0 t1 = time.time() for line in open("nucleosome.pdb"): if line =~ m/(ATOM |HETATM)/: count += 1 print count, "atoms in", time.time()-t1, "seconds" It used it own PLY-based parser to generate the Python AST. None of it would work now. :)
- eesmith 4y ago
  I realize now how much of a hack it is. The portion 'm/(ATOM |HETATM)/' could be part of valid Python expression, as: >>> ATOM = HETATM = 1 >>> m = 2 >>> m/(ATOM |HETATM)/1 2.0 so either m// is enabled only after =~, or there has to be some way to recognize the lexically correct match term -- something more powerful than the "m/[^/]*/[a-z]*" used here.

dvdkon 4y ago

I have to say I really like Python's module system. Modules as objects, scoped import by default and filesystem-backed module resolution (+sys.path) are all good choices in my opinion. Cosmetic warts like __pycache__ are unfortunate, but not deal-breakers.