大约有 43,000 项符合查询结果（耗时：0.0389秒） [XML]
How to combine two or more querysets in a Django view?
...s. For example:
>>> qs1.union(qs2, qs3)
The UNION operator selects only distinct values by default. To allow duplicate values, use the all=True
argument.
union(), intersection(), and difference() return model instances of
the type of the first QuerySet even if the arguments ...
How to change the default GCC compiler in Ubuntu?
... @thang also called cc: root@host:/root# update-alternatives --get-selections | grep '/usr/bin/gcc' cc auto /usr/bin/gcc
– jopasserat
Aug 13 '16 at 15:26
...
Setting up a common nuget packages folder for all solutions when some projects are included in multi
...t-Click on your "NuGet" solution folder and then Add->Existing Item and select \Solutions\NuGet.Config.
The reason we are doing this is so that it is visible in the solution and should help with making sure it is properly committed to your source code control. You may want to do this step for ea...
How to deal with SettingWithCopyWarning in Pandas?
...owing, which does not always work as expected, particularly when the first selection returns a copy. [see GH5390 and GH5597 for background discussion.]
df[df['A'] > 2]['B'] = new_val # new_val not set in df
The warning offers a suggestion to rewrite as follows:
df.loc[df['A'] > 2, 'B'] =...
What are the dark corners of Vim your mom never told you about? [closed]
....
viwy or viwc. Yank or change current word. Hit w multiple times to keep selecting each subsequent word, use b to move backwards
vi{ - select all text in figure brackets. va{ - select all text including {}s
vi(p - highlight everything inside the ()s and replace with the pasted text
b and e move...
How to remove unused imports from Eclipse
...rences → Java → Editor → Save Actions.
Check the option "Perform the selected actions on save".
Check the option "Organize imports".
Now every time you save your classes, eclipse will take care of removing the unused imports.
...
Do I have to guard against SQL injection if I used a dropdown?
...
$size = filter_input(INPUT_POST, "size", FILTER_VALIDATE_INT);
echo '<select name="size">';
foreach($sizes as $i => $s) {
echo '<option value="' . $i . '"' . ($i == $size ? ' selected' : '') . '>' . $s . '</option>';
}
echo '</select>';
Then you can use $size in yo...
Unfortunately MyApp has stopped. How can I solve this?
.... Alternatively, you can press alt+6. Make sure your emulator or device is selected in the Devices panel. Next, try to find the stack trace, which is shown in red. There may be a lot of stuff logged into logcat, so you may need to scroll a bit. An easy way to find the stack trace is to clear the log...
Preserving order with LINQ
...p a source element by index to a result element
AsEnumerable
Cast
Concat
Select
ToArray
ToList
Preserves Order. Elements are filtered or added, but not re-ordered.
Distinct
Except
Intersect
OfType
Prepend (new in .net 4.7.1)
Skip
SkipWhile
Take
TakeWhile
Where
Zip (new in .net 4)
Destroys O...
Stop Excel from automatically converting certain text values to dates
...qualifier if you have surrounded your values by quotes
In the third page, select every column individually and assign each the type "Text" instead of "General" to stop Excel from messing with your data.
Hope this helps you or someone with a similar problem!
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