大约有 48,000 项符合查询结果（耗时：0.0620秒） [XML]
while (1) vs. while(True) — Why is there a difference (in python 2 bytecode)?
Intrigued by this question about infinite loops in perl: while (1) Vs. for (;;) Is there a speed difference? , I decided to run a similar comparison in python. I expected that the compiler would generate the same byte code for while(True): pass and while(1): pass , but this is actually not the c...
What does the star operator mean, in a function call?
...arguments, so you can do this:
def sum(a, b):
return a + b
values = (1, 2)
s = sum(*values)
This will unpack the tuple so that it actually executes as:
s = sum(1, 2)
The double star ** does the same, only using a dictionary and thus named arguments:
values = { 'a': 1, 'b': 2 }
s = sum(*...
in_array multiple values
...
answered Sep 24 '11 at 23:51
Mark ElliotMark Elliot
65.9k1818 gold badges132132 silver badges155155 bronze badges
...
How to select rows with one or more nulls from a pandas DataFrame without listing columns explicitly
...0, 0, np.NaN], range(3), range(3)])
>>> df.isnull()
0 1 2
0 False False False
1 False True False
2 False False True
3 False False False
4 False False False
>>> df.isnull().any(axis=1)
0 False
1 True
2 True
3 False
4 False
dtype: bo...
Is unsigned integer subtraction defined behavior?
...
107
The result of a subtraction generating a negative number in an unsigned type is well-defined:
...
JavaScript function similar to Python range()
... start = 0;
}
if (typeof step == 'undefined') {
step = 1;
}
if ((step > 0 && start >= stop) || (step < 0 && start <= stop)) {
return [];
}
var result = [];
for (var i = start; step > 0 ? i < stop : i > stop; i += ...
Operation on every pair of element in a list
... module. It does exactly what you describe.
import itertools
my_list = [1,2,3,4]
for pair in itertools.product(my_list, repeat=2):
foo(*pair)
This is equivalent to:
my_list = [1,2,3,4]
for x in my_list:
for y in my_list:
foo(x, y)
Edit: There are two very similar functions as...
How to add title to subplots in Matplotlib?
...x.title.set_text('My Plot Title') seems to work too.
fig = plt.figure()
ax1 = fig.add_subplot(221)
ax2 = fig.add_subplot(222)
ax3 = fig.add_subplot(223)
ax4 = fig.add_subplot(224)
ax1.title.set_text('First Plot')
ax2.title.set_text('Second Plot')
ax3.title.set_text('Third Plot')
ax4.title.set_text(...
Scala @ operator
...
180
It enables one to bind a matched pattern to a variable. Consider the following, for instance:
...