大约有 45,000 项符合查询结果（耗时：0.0469秒） [XML]
Get index of array element faster than O(n)
... Hash[array.map.with_index.to_a] # => {"a"=>0, "b"=>1, "c"=>2}
hash['b'] # => 1
share
|
improve this answer
|
follow
|
...
Print a list in reverse order with range()?
...rameters. range(start, stop, step)
For example, to generate a list [5,4,3,2,1,0], you can use the following:
range(5, -1, -1)
It may be less intuitive but as the comments mention, this is more efficient and the right usage of range for reversed list.
...
Compare two DataFrames and output their differences side-by-side
...lar to Constantine, you can get the boolean of which rows are empty*:
In [21]: ne = (df1 != df2).any(1)
In [22]: ne
Out[22]:
0 False
1 True
2 True
dtype: bool
Then we can see which entries have changed:
In [23]: ne_stacked = (df1 != df2).stack()
In [24]: changed = ne_stacked[ne_stac...
How to iterate over a JavaScript object?
... |
edited Nov 3 '19 at 12:50
Beachhouse
4,46722 gold badges2222 silver badges3434 bronze badges
answer...
How can I include a YAML file inside another?
...
jameshfisherjameshfisher
24.3k2020 gold badges8484 silver badges137137 bronze badges
...
Grep characters before and after match?
...
3 characters before and 4 characters after
$> echo "some123_string_and_another" | grep -o -P '.{0,3}string.{0,4}'
23_string_and
share
|
improve this answer
|
...
Encode URL in JavaScript?
...
2847
Check out the built-in function encodeURIComponent(str) and encodeURI(str).
In your case, thi...
How to get the first column of a pandas DataFrame as a Series?
...>>> import pandas as pd
>>> df = pd.DataFrame({'x' : [1, 2, 3, 4], 'y' : [4, 5, 6, 7]})
>>> df
x y
0 1 4
1 2 5
2 3 6
3 4 7
>>> s = df.ix[:,0]
>>> type(s)
<class 'pandas.core.series.Series'>
>>>
================================...
Logical XOR operator in C++?
...
answered Oct 20 '09 at 19:03
Greg HewgillGreg Hewgill
783k167167 gold badges10841084 silver badges12221222 bronze badges
...
Peak-finding algorithm for Python/SciPy
... matplotlib.pyplot as plt
from scipy.signal import find_peaks
x = np.sin(2*np.pi*(2**np.linspace(2,10,1000))*np.arange(1000)/48000) + np.random.normal(0, 1, 1000) * 0.15
peaks, _ = find_peaks(x, distance=20)
peaks2, _ = find_peaks(x, prominence=1) # BEST!
peaks3, _ = find_peaks(x, width=20)
p...