大约有 47,000 项符合查询结果（耗时：0.0334秒） [XML]
Converting a column within pandas dataframe from int to string
...
In [16]: df = DataFrame(np.arange(10).reshape(5,2),columns=list('AB'))
In [17]: df
Out[17]:
A B
0 0 1
1 2 3
2 4 5
3 6 7
4 8 9
In [18]: df.dtypes
Out[18]:
A int64
B int64
dtype: object
Convert a series
In [19]: df['A'].apply(str)
Ou...
Why am I getting a “401 Unauthorized” error in Maven?
Why am I getting a "401 Unauthorized" error in Maven?
21 Answers
21
...
Putting an if-elif-else statement on one line?
...st likely violate PEP-8 where it is mandated that lines should not exceed 80 characters in length.
It's also against the Zen of Python: "Readability counts". (Type import this at the Python prompt to read the whole thing).
You can use a ternary expression in Python, but only for expressions, not f...
Create list of single item repeated N times
...
809
You can also write:
[e] * n
You should note that if e is for example an empty list you get a...
Using numpy to build an array of all combinations of two arrays
...
10 Answers
10
Active
...
Performance of FOR vs FOREACH in PHP
First of all, I understand in 90% of applications the performance difference is completely irrelevant, but I just need to know which is the faster construct. That and...
...
Fast way to get image dimensions (not filesize)
...re the better. I emphasize fast because my images are quite big (up to 250 MB) and it takes soooo long to get the size with ImageMagick's identify because it obviously reads the images as a whole first.
...
How do I create a list of random numbers without duplicates?
I tried using random.randint(0, 100) , but some numbers were the same. Is there a method/module to create a list unique random numbers?
...
Count occurrences of a char in plain text file
...
|
edited Oct 21 '09 at 21:45
answered Oct 21 '09 at 21:37
...
Expand a random range from 1–5 to 1–7
...2, 3 },
{ 4, 5, 6, 7, 1 },
{ 2, 3, 4, 5, 6 },
{ 7, 0, 0, 0, 0 }
};
int result = 0;
while (result == 0)
{
int i = rand5();
int j = rand5();
result = vals[i-1][j-1];
}
return result;
}
How does it work? Think of it like this: i...