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How do I check if a number is a palindrome?
...ler problems. When I solved it in Haskell I did exactly what you suggest, convert the number to a String. It's then trivial to check that the string is a pallindrome. If it performs well enough, then why bother making it more complex? Being a pallindrome is a lexical property rather than a mathe...
Fast permutation -> number -> permutation mapping algorithms
...lation w[k-1] = k! is easily proved by induction.)
The number we get from converting our sequence will then be the sum of s[k] * w[k], with k running from 0 to n-1. Here s[k] is the k'th (rightmost, starting at 0) element of the sequence. As an example, take our {1, 2, 0, 1, 0}, with the rightmost ...
how to convert from int to char*?
...
Also, you need 12 characters to convert a 32-bit integer to a nul-terminated base-10 representation. 10 isn't enough for -2147483647.
– Steve Jessop
Jun 1 '12 at 9:12
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Converting int to bytes in Python 3
...s much more expensive, so never use lists when you can use tuples. You can convert bigger integers by using int.to_bytes(3, "little").
Initializing bytes with a given length makes sense and is the most useful, as they are often used to create some type of buffer for which you need some memory of gi...
Assign pandas dataframe column dtypes
... pd.to_timedelta and pd.to_numeric
(As mentioned below, no more "magic", convert_objects has been deprecated in 0.17)
df = pd.DataFrame({'x': {0: 'a', 1: 'b'}, 'y': {0: '1', 1: '2'}, 'z': {0: '2018-05-01', 1: '2018-05-02'}})
df.dtypes
x object
y object
z object
dtype: object
df
x ...
Why is printing to stdout so slow? Can it be sped up?
...andle to stdout with a big buffer yourself, using something like os.fdopen(sys.stdout.fileno(), 'w', BIGNUM). This would almost never be useful, though: almost all applications would have to remember to explicitly flush after each line of user-intended output.
– Pi Delport
...
Importing from a relative path in Python
...For example, it's popular with Django users.
You can add Common/ to your sys.path (the list of paths python looks at to import things):
import sys, os
sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'Common'))
import Common
os.path.dirname(__file__) just gives you the directory th...
How to convert a boolean array to an int array
I use Scilab, and want to convert an array of booleans into an array of integers:
6 Answers
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Python - Get path of root project structure
...
To get the path of the "root" module, you can use:
import os
import sys
os.path.dirname(sys.modules['__main__'].__file__)
But more interestingly if you have an config "object" in your top-most module you could -read- from it like so:
app = sys.modules['__main__']
stuff = app.config.somefun...
How can I convert bigint (UNIX timestamp) to datetime in SQL Server?
How can I convert UNIX timestamp (bigint) to DateTime in SQL Server?
15 Answers
15
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