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TypeError: 'NoneType' object is not iterable in Python
... Correct, But the common scenario author intended here is totally to skip the for loop instead of raising an exception. Python's design is flawed here. When None is treated as an iterable it must return empty list at least. This exception never helped anyone in real life other than m...
Python argparse ignore unrecognised arguments
Optparse, the old version just ignores all unrecognised arguments and carries on. In most situations, this isn't ideal and was changed in argparse. But there are a few situations where you want to ignore any unrecognised arguments and parse the ones you've specified.
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Regular Expression for alphanumeric and underscores
...o or more of the given characters
$ : end of string
If you don't want to allow empty strings, use + instead of *.
As others have pointed out, some regex languages have a shorthand form for [a-zA-Z0-9_]. In the .NET regex language, you can turn on ECMAScript behavior and use \w as a shorthand (y...
Is there a generator version of `string.split()` in Python?
...plitlines chops off the trainling newline though (something that I don't really like...); if you wanted to replicated that part of the behavior, you could use grouping: (m.group(2) or m.group(3) for m in re.finditer('((.*)\n|(.+)$)', s)). PS: I guess the outer paren in the RE are not needed; I just ...
Multiple Updates in MySQL
...has new records then i will end up inserting only the ids and count except all other information. if and only if there is an entry for the id then it should update else it should skip. what shall i do?
– Jayapal Chandran
Aug 30 '10 at 13:30
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WatiN or Selenium? [closed]
.... It will be a major upgrade to the current CTP 2.0 versions and will basically give you the same functionality to automate FireFox and IE as version 1.3.0 offers for automating IE.
So no concerns there.
Hope this helps in making your choice
Jeroen van Menen
Lead dev WatiN
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How can I use numpy.correlate to do autocorrelation?
...olution, C(t)=∑ -∞ < i < ∞ aivt+i where -∞ < t < ∞, allows for results from -∞ to ∞, but you obviously can't store an infinitely long array. So it has to be clipped, and that is where the mode comes in. There are 3 different modes: full, same, & valid:
"full" mode r...
Why does modern Perl avoid UTF-8 by default?
...?????????????????????
Set your PERL_UNICODE envariable to AS. This makes all Perl scripts decode @ARGV as UTF‑8 strings, and sets the encoding of all three of stdin, stdout, and stderr to UTF‑8. Both these are global effects, not lexical ones.
At the top of your source file (program, module, l...
Regular expression to allow spaces between words
I want a regular expression that prevents symbols and only allows letters and numbers. The regex below works great, but it doesn't allow for spaces between words.
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PhoneGap: Detect if running on desktop browser
...he 'desktop' and mobile versions. I want to be able to detect if PhoneGap calls will work (ie, is the user on a mobile device that will support PhoneGap).
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