大约有 48,000 项符合查询结果（耗时：0.0272秒） [XML]
Unique BooleanField value in Django?
... save method of the model and if you've set the boolean to True, make sure all others are set to False.
from django.db import transaction
class Character(models.Model):
name = models.CharField(max_length=255)
is_the_chosen_one = models.BooleanField()
def save(self, *args, **kwargs):
...
What's the difference between process.cwd() vs __dirname?
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Does this mean that process.cwd() is synonym to . for all cases except for require()?
– Alexander Gonchiy
Aug 29 '15 at 9:44
11
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How to customize the background/border colors of a grouped table view cell?
...later UITableViewCell now has a backgroundColor property that makes this really easy (especially in combination with the [UIColor colorWithPatternImage:] initializer). But I'll leave the 2.0 version of the answer here for anyone that needs it…
It's harder than it really should be. Here's how I ...
Circular (or cyclic) imports in Python
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There was a really good discussion on this over at comp.lang.python last year. It answers your question pretty thoroughly.
Imports are pretty straightforward really. Just remember the following:
'import' and 'from xxx import yyy' ...
Maven fails to find local artifact
Occasionally maven complains that a particular dependency, which is built and packaged locally, cannot be found in the local repository while building another project that has it as a dependency. We get an error like:
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Is there a MySQL option/feature to track history of changes to records?
...ant to audit the changes to the data - who did what and when?", you can usually use audit tables (as per the trigger example Keethanjan posted). I'm not a huge fan of triggers, but it has the great benefit of being relatively painless to implement - your existing code doesn't need to know about the ...
How do I print a list of “Build Settings” in Xcode project?
... 4.1
ACTION build
AD_HOC_CODE_SIGNING_ALLOWED NO
ALTERNATE_GROUP staff
ALTERNATE_MODE u+w,go-w,a+rX
ALTERNATE_OWNER username
ALWAYS_SEARCH_USER_PATHS YES...
Detect URLs in text with JavaScript
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Finally a regex that really works in most obvious case! This one deserves a bookmarking. I tested thousands examples from googles search until i find this.
– Ismael
Jan 16 '15 at 15:11
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How to get current timestamp in milliseconds since 1970 just the way Java gets
...e UNIX epoch, but the spec only says it must be the system-wide real time wall clock. There is no requirement for the steady_clock to match reality, only that it only move forward.
– Oz.
Jul 27 '15 at 23:22
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Delete column from pandas DataFrame
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This answer isn't really correct - the pandas developers didn't, but that doesn't mean it is hard to do.
– wizzwizz4
Sep 30 '17 at 9:42
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