大约有 48,000 项符合查询结果（耗时：0.0516秒） [XML]
Sqlite primary key on multiple columns
...LE something (
column1, column2, value, PRIMARY KEY (column1, column2));
Now this works without any warning:
sqlite> insert into something (value) VALUES ('bla-bla');
sqlite> insert into something (value) VALUES ('bla-bla');
sqlite> select * from something;
NULL|NULL|bla-bla
NULL|NULL|bl...
How can I open Java .class files in a human-readable way?
... As long as the link goes somewhere, I suppose it's good. I wouldn't know if there's now a better Java decompiler, as I haven't used Java since long ago.
– DarenW
Mar 30 at 20:20
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Delete last char of string
...s searching the string. It could be removing from somewhere in the middle. Now the maintenance programmer has to examine all uses of the method, to see what was trying to be accomplished. Not a good method to call, for this simple need of removing from the end of a string. Sorry for all the critici...
How do I center text horizontally and vertically in a TextView?
...avoMaciel so, basically xml unless it needs to be modified dynamically ... Now i got it. Thanks for your simple and useful answer !
– kenju
Nov 6 '15 at 0:46
add a comment
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How to use “/” (directory separator) in both Linux and Windows in Python?
...
It's 2020, so this should now be the accepted answer. The Python devs added it to overcome problems in os, and it makes everything easier. Ex path.read_text(encoding="utf8"), path.read_bytes(), path.resolve(), path.unlink(), ...
–...
What's the difference between a continuation and a callback?
..., 4));
function pythagoras(x, y) {
return x * x + y * y;
}
Now if every operation (including addition, multiplication, etc.) were written in the form of functions then we would have:
console.log(pythagoras(3, 4));
function pythagoras(x, y) {
return add(square(x), square(...
Python: How to ignore an exception and proceed? [duplicate]
...you in a singleton tuple, and I won't tell you when I do one or the other; now your job is to always give me back the integer? Perhaps you would appreciate being able to write something like with suppress(TypeError): return data[0] (longer example: pastebin.com/gcvAGqEP)
– Air
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Extract a regular expression match
...
One way would be this:
test <- regexpr("[0-9]+","aaa12456xxx")
Now, notice regexpr gives you the starting and ending indices of the string:
> test
[1] 4
attr(,"match.length")
[1] 5
So you can use that info with substr function
substr("aaa12456xxx",test,test+attr(test,"match.le...
How to trigger a file download when clicking an HTML button or JavaScript
This is crazy but I don't know how to do this, and because of how common the words are, it's hard to find what I need on search engines. I'm thinking this should be an easy one to answer.
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How to get a value from a cell of a dataframe?
...as 10.1/13.1
I upgraded from 10.1 to 13.1, before iloc is not available.
Now with 13.1, iloc[0]['label'] gets a single value array rather than a scalar.
Like this:
lastprice=stock.iloc[-1]['Close']
Output:
date
2014-02-26 118.2
name:Close, dtype: float64
...