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Pandas count(distinct) equivalent
...if I have multiple columns that I want to be unique together, like in .drop_duplicates(subset=['col1','col2'])?
– ErnestScribbler
Oct 2 '17 at 8:10
4
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Which is the fastest algorithm to find prime numbers?
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Actually I don't think primegen is the fastest, or even the second-fastest; yafu and primesieve are both faster in general, I think, and certainly over 2^32. Both are (modified) sieves of Eratosthenes rather than the Atkin-Berns...
Is it possible to set the equivalent of a src attribute of an img tag in CSS?
...urse you can use padding-left /
padding-top to make rectangular images.
Finally, the new image is put there using background.
If the new background image is too large or too small, I recommend using background-size for example: background-size:cover; which fits your image into the allotted space.
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How do I find out which keystore was used to sign an app?
...ture algorithm name: SHA1withRSA
Then use the keytool again to print out all the aliases of your signing keystore:
keytool -list -keystore my-signing-key.keystore
You will get a list of aliases and their certificate fingerprint:
android_key, Jan 23, 2010, PrivateKeyEntry,
Certificate fingerpri...
Delete all tags from a Git repository
I want to delete all the tags from a Git repository. How can I do that?
11 Answers
11
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Installing PIL with pip
I am trying to install PIL (the Python Imaging Library) using the command:
21 Answers
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Where in a virtualenv does the custom code go?
... instance, if I were building a WSGI application and created a virtualenv called foobar I would start with a directory structure like:
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How do I pass a variable by reference?
...le type
Let's try to modify the list that was passed to a method:
def try_to_change_list_contents(the_list):
print('got', the_list)
the_list.append('four')
print('changed to', the_list)
outer_list = ['one', 'two', 'three']
print('before, outer_list =', outer_list)
try_to_change_list_...
What is the official “preferred” way to install pip and virtualenv systemwide?
...here/how do you install setuptools-0.8? Looks like you are just grabbing ez_setup.py for a "lightweight version" of getting pip. I'd do the same but fear that it will break in the near future and I'll get stuck here again (like I always do)
– Steven Lu
Jul 13 '...
Swift - Convert to absolute value
...alue.magnitude) // prints: 5
#2. Get absolute value of an Int from abs(_:) method
Swift has a global numeric function called abs(_:) method. abs(_:) has the following declaration:
func abs<T>(_ x: T) -> T where T : Comparable, T : SignedNumeric
Returns the absolute value of the g...