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In a django model custom save() method, how should you identify a new object?

... Updated: With the clarification that self._state is not a private instance variable, but named that way to avoid conflicts, checking self._state.adding is now the preferable way to check. self.pk is None: returns True within a new Model object, unless the object...
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Finding local maxima/minima with Numpy in a 1D numpy array

...ntries in the 1d array a smaller than their neighbors, you can try numpy.r_[True, a[1:] < a[:-1]] & numpy.r_[a[:-1] < a[1:], True] You could also smooth your array before this step using numpy.convolve(). I don't think there is a dedicated function for this. ...
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How do I represent a hextile/hex grid in memory?

... Board: # Layout is just a double list of Tiles, some will be None def __init__(self, layout=None): self.numRows = len(layout) self.numCols = len(layout[0]) self.hexagons = [[None for x in xrange(self.numCols)] for x in xrange(self.numRows)] self.edges = [[None for x in xrange(s...
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How to check 'undefined' value in jQuery

... and fill them with a default value say 0.0: var aFieldsCannotBeNull=['ast_chkacc_bwr','ast_savacc_bwr']; jQuery.each(aFieldsCannotBeNull,function(nShowIndex,sShowKey) { var $_oField = jQuery("input[name='"+sShowKey+"']"); if($_oField.val().trim().length === 0){ $_oField.val('0.0') ...
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How do you split and unsplit a window/view in Eclipse IDE?

...ditor. Current shortcut for splitting is: Azerty keyboard: Ctrl + _ for split horizontally, and Ctrl + { for split vertically. Qwerty US keyboard: Ctrl + Shift + - (accessing _) for split horizontally, and Ctrl + Shift + [ (accessing {) for split vertically. MacOS - Qwe...
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How to create an object for a Django model with a many to many field?

... m2m relations from unsaved objects. If you have the pks, try this: sample_object = Sample() sample_object.save() sample_object.users.add(1,2) Update: After reading the saverio's answer, I decided to investigate the issue a bit more in depth. Here are my findings. This was my original suggestion...
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UnicodeDecodeError: 'utf8' codec can't decode byte 0xa5 in position 0: invalid start byte

... I switched this simply by defining a different codec package in the read_csv() command: encoding = 'unicode_escape' Eg: import pandas as pd data = pd.read_csv(filename, encoding= 'unicode_escape') share | ...
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Convert a float64 to an int in Go

...onv" ) func main() { floats := []float64{1.9999, 2.0001, 2.0} for _, f := range floats { t := int(f) s := fmt.Sprintf("%.0f", f) if i, err := strconv.Atoi(s); err == nil { fmt.Println(f, t, i) } else { fmt.Println(f, t, err) } ...
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Is there a way to make mv create the directory to be moved to if it doesn't exist?

... this one-liner (in bash): mkdir --parents ./some/path/; mv yourfile.txt $_ Breaking that down: mkdir --parents ./some/path creates the directory (including all intermediate directories), after which: mv yourfile.txt $_ moves the file to that directory ($_ expands to the last argument passe...
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std::mutex 加锁抛 _DEVICE_OR_RESOURCE_BUSY 异常 - C/C++ - 清泛网 - 专注C/C++及内核技术

std::mutex 加锁抛 _DEVICE_OR_RESOURCE_BUSY 异常device_or_resource_busy最近遇到一个崩溃,在 std::lock_guard<std::mutex> lock(mutex_); 的地方,抛出了_DEVICE_OR_RESOURCE_BUSY 的异常。最终查出原因是:同一个线程对同一个mutex二次加锁导致的 最近遇到...