大约有 47,000 项符合查询结果（耗时：0.0305秒） [XML]
How to validate an email address using a regular expression?
...
+50
The fully RFC 822 compliant regex is inefficient and obscure because of its length. Fortunately, RFC 822 was superseded twice and the...
What do “branch”, “tag” and “trunk” mean in Subversion repositories?
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answered Aug 19 '08 at 13:35
Jon LimjapJon Limjap
87.7k1414 gold badges9494 silver badges147147 bronze badges
...
Remove outline from select box in FF
...he color of the dotted border. So say if you do...
select {
color: rgba(0,0,0,0);
}
Firefox will render the dotted border transparent. But of course your text will be transparent too! So we must somehow display the text. text-shadow comes to the rescue:
select {
color: rgba(0,0,0,0);
text-...
How do I convert a TimeSpan to a formatted string? [duplicate]
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|
edited Aug 16 '09 at 17:51
answered May 8 '09 at 22:22
...
Delete element in a slice
... arguments to a variadic function.
So what this line does:
a = append(a[:0], a[1:]...)
is essentially:
a = append(a[:0], a[1], a[2])
Now, you may be wondering, why not just do
a = append(a[1:]...)
Well, the function definition of append is
func append(slice []Type, elems ...Type) []Type
...
Why is address zero used for the null pointer?
...s a pointer with the value zero if it can't get me memory; I use if (p != 0) all the time to make sure passed pointers are valid, etc.
...
What is Bit Masking?
...
250
A mask defines which bits you want to keep, and which bits you want to clear.
Masking is the ac...
How to avoid reinstalling packages when building Docker image for Python projects?
...ree
.
├── Dockerfile
├── requirements.txt
└── run.py
0 directories, 3 file
# Dockerfile
FROM dockerfile/python
WORKDIR /srv
ADD ./requirements.txt /srv/requirements.txt
RUN pip install -r requirements.txt
ADD . /srv
CMD python /srv/run.py
# requirements.txt
pytest==2.3.4
# ...
pandas: filter rows of DataFrame with operator chaining
... boolean index.
In [96]: df
Out[96]:
A B C D
a 1 4 9 1
b 4 5 0 2
c 5 5 1 0
d 1 3 9 6
In [99]: df[(df.A == 1) & (df.D == 6)]
Out[99]:
A B C D
d 1 3 9 6
If you want to chain methods, you can add your own mask method and use that one.
In [90]: def mask(df, key, ...
Sample random rows in dataframe
...
460
First make some data:
> df = data.frame(matrix(rnorm(20), nrow=10))
> df
X1 ...