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Delete column from pandas DataFrame
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As you've guessed, the right syntax is
del df['column_name']
It's difficult to make del df.column_name work simply as the result of syntactic limitations in Python. del df[name] gets translated to df.__delitem__(name) under the covers by Python.
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how to get the current working directory's absolute path from irb
...ssible from irb? Apparently from a script it's possible using File.expand_path(__FILE__)
6 Answers
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In Python, how do I indicate I'm overriding a method?
...an think of a better solution please post it here!
def overrides(interface_class):
def overrider(method):
assert(method.__name__ in dir(interface_class))
return method
return overrider
It works as follows:
class MySuperInterface(object):
def my_method(self):
p...
PHP array_filter with arguments
...rgument):
class LowerThanFilter {
private $num;
function __construct($num) {
$this->num = $num;
}
function isLower($i) {
return $i < $this->num;
}
}
Usage (demo):
$arr = array(7, 8, 9, 10, 11, 12, 13);
$matches = ...
What integer hash function are good that accepts an integer hash key?
... seems to be based on the blog article Better Bit Mixing (mix 13).
uint64_t hash(uint64_t x) {
x = (x ^ (x >> 30)) * UINT64_C(0xbf58476d1ce4e5b9);
x = (x ^ (x >> 27)) * UINT64_C(0x94d049bb133111eb);
x = x ^ (x >> 31);
return x;
}
For Java, use long, add L to the...
Pythonic way to find maximum value and its index in a list?
...many options, for example:
import operator
index, value = max(enumerate(my_list), key=operator.itemgetter(1))
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How to disable GCC warnings for a few lines of code
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TL;DR: If it works, avoid, or use specifiers like __attribute__, otherwise _Pragma.
This is a short version of my blog article
Suppressing Warnings in GCC and Clang.
Consider the following Makefile
CPPFLAGS:=-std=c11 -W -Wall -pedantic -Werror
.PHONY: all
all: puts
fo...
How to track untracked content?
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You have added vendor/plugins/open_flash_chart_2 as “gitlink” entry, but never defined it as a submodule. Effectively you are using the internal feature that git submodule uses (gitlink entries) but you are not using the submodule feature itself.
You pr...
difference between variables inside and outside of __init__()
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Variable set outside __init__ belong to the class. They're shared by all instances.
Variables created inside __init__ (and all other method functions) and prefaced with self. belong to the object instance.
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How to sort two lists (which reference each other) in the exact same way
... of 10000 random ints): %timeit index = range(len(l1)); index.sort(key=l1.__getitem__); map(l1.__getitem__, index); map(l2.__getitem__, index) 100 loops, best of 3: 8.04 ms per loop (vs 9.17 ms, 9.07 ms for senderle's timits)
– Quantum7
Aug 12 '13 at 21:35
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