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从功能上来说大致分为3类，在连接菜单下：
但是每种类型下面仍...
Insert a row to pandas dataframe
...
Just assign row to a particular index, using loc:
df.loc[-1] = [2, 3, 4] # adding a row
df.index = df.index + 1 # shifting index
df = df.sort_index() # sorting by index
And you get, as desired:
A B C
0 2 3 4
1 5 6 7
2 7 8 9
See in Pandas documentation Indexing: Se...
How to return a part of an array in Ruby?
...ndex) are out of range.
a = [ "a", "b", "c", "d", "e" ]
a[2] + a[0] + a[1] #=> "cab"
a[6] #=> nil
a[1, 2] #=> [ "b", "c" ]
a[1..3] #=> [ "b", "c", "d" ]
a[4..7] #=> [ "e...
Focus Input Box On Load
...ction() {
var input = document.getElementById("myinputbox").focus();
}
2) How to place cursor at the end of the input text?
Here's a non-jQuery solution with some borrowed code from another SO answer.
function placeCursorAtEnd() {
if (this.setSelectionRange) {
// Double the length bec...
C++ performance challenge: integer to std::string conversion
...
#include <string>
const char digit_pairs[201] = {
"00010203040506070809"
"10111213141516171819"
"20212223242526272829"
"30313233343536373839"
"40414243444546474849"
"50515253545556575859"
"60616263646566676869"
"70717273747576777879"
"8081828384858...
Function to calculate distance between two coordinates
...ording to Google Maps, the distance between these coordinates (from 59.3293371,13.4877472 to 59.3225525,13.4619422 ) are 2.2 kilometres while the function returns 1.6 kilometres. How can I make this function return the correct distance?
...
How do you convert a byte array to a hexadecimal string, and vice versa?
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Pandas: drop a level from a multi-level column index?
...
321
You can use MultiIndex.droplevel:
>>> cols = pd.MultiIndex.from_tuples([("a", "b"), (...
Explicitly select items from a list or tuple
...
list( myBigList[i] for i in [87, 342, 217, 998, 500] )
I compared the answers with python 2.5.2:
19.7 usec: [ myBigList[i] for i in [87, 342, 217, 998, 500] ]
20.6 usec: map(myBigList.__getitem__, (87, 342, 217, 998, 500))
22.7 usec: itemgetter(87, 342, ...
How to perform element-wise multiplication of two lists?
...
287
Use a list comprehension mixed with zip():.
[a*b for a,b in zip(lista,listb)]
...