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How is a CRC32 checksum calculated?
... 1100001010 = Quotient (nobody cares about the quotient)
_______________
10011 ) 11010110110000 = Augmented message (1101011011 + 0000)
=Poly 10011,,.,,....
-----,,.,,....
10011,.,,....
10011,.,,....
-----,.,,....
00001.,,....
...
while (1) vs. while(True) — Why is there a difference (in python 2 bytecode)?
...oes.
Here's 2.7:
>>> dis.dis('True == 1')
1 0 LOAD_GLOBAL 0 (True)
3 LOAD_CONST 1 (1)
6 COMPARE_OP 2 (==)
9 RETURN_VALUE
>>> dis.dis('True == 1')
1 0 LOAD_GLOBAL ...
'id' is a bad variable name in Python
...() is a fundamental built-in:
Help on built-in function id in module
__builtin__:
id(...)
id(object) -> integer
Return the identity of an object. This is guaranteed to be unique among
simultaneously existing objects. (Hint: it's the object's memory
address.)
In g...
What is the maximum recursion depth in Python, and how to increase it?
...mple context manager like this:
import sys
class recursionlimit:
def __init__(self, limit):
self.limit = limit
self.old_limit = sys.getrecursionlimit()
def __enter__(self):
sys.setrecursionlimit(self.limit)
def __exit__(self, type, value, tb):
sys.setr...
Pandas - How to flatten a hierarchical index in columns
... would be to set the columns to the top level:
df.columns = df.columns.get_level_values(0)
Note: if the to level has a name you can also access it by this, rather than 0.
.
If you want to combine/join your MultiIndex into one Index (assuming you have just string entries in your columns) you cou...
How can I check for Python version in a program that uses new language features?
...oesn't have ternary
Also, with is available in Python 2.5, just add from __future__ import with_statement.
EDIT: to get control early enough, you could split it into different .py files and check compatibility in the main file before importing (e.g. in __init__.py in a package):
# __init__.py
#...
Determine if variable is defined in Python [duplicate]
...()
if you want to be pedantic, you can check the builtins too
'a' in vars(__builtins__)
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Any reason not to use '+' to concatenate two strings?
...ucture, especially if it is growing. With list you can use list.extend(list_of_items) and list.append(item) which are much faster when concatenating stuff dynamically.
– Antti Haapala
Sep 11 '12 at 9:56
...
Test if a variable is a list or tuple
...
How about: hasattr(a, "__iter__") ?
It tells if the object returned can be iterated over as a generator. By default, tuples and lists can, but not the string types.
share...
PowerShell script to return versions of .NET Framework on a machine?
...up\NDP' -recurse |
Get-ItemProperty -name Version,Release -EA 0 |
Where { $_.PSChildName -match '^(?!S)\p{L}'} |
Select PSChildName, Version, Release
Based on the MSDN article, you could build a lookup table and return the marketing product version number for releases after 4.5:
$Lookup = @{
...