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What's the difference between lists enclosed by square brackets and parentheses in Python?
...you can change its contents:
>>> x = [1,2]
>>> x.append(3)
>>> x
[1, 2, 3]
while tuples are not:
>>> x = (1,2)
>>> x
(1, 2)
>>> x.append(3)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: '...
How to sort Counter by value? - python
...;> from collections import Counter
>>> x = Counter({'a':5, 'b':3, 'c':7})
>>> x.most_common()
[('c', 7), ('a', 5), ('b', 3)]
It'll do so in the most efficient manner possible; if you ask for a Top N instead of all values, a heapq is used instead of a straight sort:
>>&g...
Switch case with fallthrough?
...
314
Use a vertical bar (|) for "or".
case "$C" in
"1")
do_this()
;;
"2" | "3")
do_wha...
Need a simple explanation of the inject method
... |
edited Apr 2 '09 at 16:37
answered Apr 2 '09 at 16:31
Dr...
How to concatenate twice with the C preprocessor and expand a macro as in “arg ## _ ## MACRO”?
...
Standard C Preprocessor
$ cat xx.c
#define VARIABLE 3
#define PASTER(x,y) x ## _ ## y
#define EVALUATOR(x,y) PASTER(x,y)
#define NAME(fun) EVALUATOR(fun, VARIABLE)
extern void NAME(mine)(char *x);
$ gcc -E xx.c
# 1 "xx.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 1...
How to overcome TypeError: unhashable type: 'list'
...else:
d[key] = [value]
print d
# {'AAA': ['111', '112'], 'AAC': ['123'], 'AAB': ['111']}
Note that if you are using Python 3.x, you'll have to make a minor adjustment to get it work properly. If you open the file with rb, you'll need to use line = line.split(b'x') (which makes sure you are ...
Difference between '..' (double-dot) and '…' (triple-dot) in range generation?
... |
edited Dec 21 '16 at 0:33
answered Mar 13 '12 at 19:48
A...
Sample random rows in dataframe
...rnorm(20), nrow=10))
> df
X1 X2
1 0.7091409 -1.4061361
2 -1.1334614 -0.1973846
3 2.3343391 -0.4385071
4 -0.9040278 -0.6593677
5 0.4180331 -1.2592415
6 0.7572246 -0.5463655
7 -0.8996483 0.4231117
8 -1.0356774 -0.1640883
9 -0.3983045 0.7157506
10 -0.9060305 2.3234...
How to delete an element from an array in C#
...
342
If you want to remove all instances of 4 without needing to know the index:
LINQ: (.NET Frame...
How to update Python?
...will stop receiving official updates from python.org in 2020. Also, Python-3.7 has been released. Check out Python-Future on how to make your Python-2 code compatible with Python-3. For updating conda, the documentation now recommends using conda update --all in each of your conda environments to up...