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How to write header row with csv.DictWriter?
...ion "functionality", I'd prefer to code it myself; that way you can report ALL "extras" with the keys and values, not just the first extra key. What is a real nuisance with DictWriter is that if you've verified the keys yourself as each dict was being built, you need to remember to use extrasaction=...
Why do you need explicitly have the “self” argument in a Python method?
... to make things like this explicit rather than based on a rule.
Additionally, since nothing is implied or assumed, parts of the implementation are exposed. self.__class__, self.__dict__ and other "internal" structures are available in an obvious way.
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Read file from line 2 or skip header row
... This is fine UNTIL the file is too large to read. This is fine for small files.
– CppLearner
Feb 5 '18 at 2:05
1
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How to debug heap corruption errors?
...nctionality was in Application Verifier.
Electric Fence (aka "efence"), dmalloc, valgrind, and so forth are all worth mentioning, but most of these are much easier to get running under *nix than Windows. Valgrind is ridiculously flexible: I've debugged large server software with many heap issues u...
How exactly does a generator comprehension work?
... generator expression is like a list comprehension, but instead of finding all the items you're interested and packing them into list, it waits, and yields each item out of the expression, one by one.
>>> my_list = [1, 3, 5, 9, 2, 6]
>>> filtered_list = [item for item in my_list i...
Verifying that a string contains only letters in C#
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This assumes a latin alphabet, where Char.IsLetter allows for non-latin alphabets.
– Paul van Brenk
Jul 28 '09 at 7:31
5
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Change column type from string to float in Pandas
...ost) any other type (even if it's not necessarily sensible to do so). Also allows you to convert to categorial types (very useful).
infer_objects() - a utility method to convert object columns holding Python objects to a pandas type if possible.
convert_dtypes() - convert DataFrame columns to the ...
Why is GHC so large/big?
...
It's a bit silly really. Every library that comes with GHC is provided in no less than 4 flavours:
static
dynamic
profiled
GHCi
The GHCi version is just the static version linked together in a single .o file. The other three versions all ...
When should one use a spinlock instead of mutex?
...eed, because the mutex is already locked, it will go to sleep, immediately allowing another thread to run. It will continue to sleep until being woken up, which will be the case once the mutex is being unlocked by whatever thread was holding the lock before. When a thread tries to lock a spinlock an...
What is a method that can be used to increment letters?
...ded to expand it a bit beyond the scope of the original question to potentially help people who are stumbling on this from Google.
I find that what I often want is something that will generate sequential, unique strings in a certain character set (such as only using letters), so I've updated this a...