61–70 of 83 posts
Is it just me or is dict#setdefualt a terribly named function? I just learned of it here, and I was excited that it would set the default value for the dictionary, when instead it performs something like: (self, key, default) => self[key] = (key in self ? self[key] : default) I'd prefer something like "dict#createifnotexists", but better.
In the section "Inline -> Comprehension", isn't this: = (i+5 for i in range(10)) # (5, 6, ..., 14) really a generator expression?
So to get a list of unique values you suggest I convert to a dictionary and then convert back to a list? Is this the Python way? I dunno it seems like acrobatics no_duplicates = list(dict.fromkeys( ))
no_duplicates = set()Earlier quoted context omitted.
I came here to say exactly the opposite. The angle brackets mean that every single example is a syntax error. If you are going to write a cheatsheet with samples of Python code, why not write it in valid Python? This is clearly aimed at beginners as the samples are or very basic things, yet this is going to be confusing to them as they will think that ` ` is syntax. Have a look at the Python docs for much better ways…
I think the author of this document is trying to differentiate between types (broad notions of course -- there's no type called 'num' in Python). The Python docs (example here[1]) on the other hand limit themselves to {}, [] and () to differentiate between dicts, lists and tuples, but doesn't really differentiate between these and the more generalized notions of collections/iterators/element, etc. As someone who code…
Earlier quoted context omitted.
I think the author of this document is trying to differentiate between types (broad notions of course -- there's no type called 'num' in Python). The Python docs (example here[1]) on the other hand limit themselves to {}, [] and () to differentiate between dicts, lists and tuples, but doesn't really differentiate between these and the more generalized notions of collections/iterators/element, etc. As someone who code…
But he could achieve exactly the same thing by using descriptive variable names without the angle brackets. Admittedly he can't use `list` as it's a built-in but `a_list` or `list_` would be much better than ` `.
In the section "Inline -> Comprehension", isn't this: = (i+5 for i in range(10)) # (5, 6, ..., 14) really a generator expression?
Yes, although there is a saying that "every generator is an iterator, but not every iterator is a generator". But then again generator has a bunch of methods (close, gi_frame, gi_yieldfrom, throw, gi_code, gi_running, send) that iterators don't have... I really don't know if is correct enough here, or should I use (that I don't use anywhere else and could be confusing).
= ( f(i) for i in )
where f() is some function of i.
Is it just me or is dict#setdefualt a terribly named function? I just learned of it here, and I was excited that it would set the default value for the dictionary, when instead it performs something like: (self, key, default) => self[key] = (key in self ? self[key] : default) I'd prefer something like "dict#createifnotexists", but better.
However, when I start development of new code I always use a script that starts off with traceback and pdb, something like this:
#!/usr/bin/env python
import traceback
import pdb
import sys
def main():
# some WIP code that maybe raises an exception
raise BaseException("oh no, exception!")
return 0
if __name__ == "__main__":
try:
ret = main()
except:
traceback.print_exc()
pdb.post_mortem()
sys.exit(ret)
For me this is the best quick reference for Python (2.7 unfortunately): http://rgruet.free.fr/PQR27/PQR2.7.html
Are there any available for Ruby or Linux?