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How do I add a placeholder on a CharField in Django?

...t specify the field (e.g. for some dynamic method), you can use this: def __init__(self, *args, **kwargs): super(MyForm, self).__init__(*args, **kwargs) self.fields['email'].widget.attrs['placeholder'] = self.fields['email'].label or 'email@address.nl' It also allows the placeholder to de...
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Convert base64 string to ArrayBuffer

... Try this: function _base64ToArrayBuffer(base64) { var binary_string = window.atob(base64); var len = binary_string.length; var bytes = new Uint8Array(len); for (var i = 0; i < len; i++) { bytes[i] = binary_string.char...
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Using numpy to build an array of all combinations of two arrays

... TypeError: slice indices must be integers or None or have an __index__ method thrown by cartesian(arrays[1:], out=out[0:m,1:]) – Boern Sep 25 '17 at 15:48 ...
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Is gcc std::unordered_map implementation slow? If so - why?

...t, how much slower our concurrent hash map is compared with std::unordered_map . 3 Answers ...
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String's Maximum length in Java - calling length() method

...he maximum length that would be returned by the method would be Integer.MAX_VALUE, which is 2^31 - 1 (or approximately 2 billion.) In terms of lengths and indexing of arrays, (such as char[], which is probably the way the internal data representation is implemented for Strings), Chapter 10: Arrays ...
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Return None if Dictionary key is not available

...ldn't work out what I was doing wrong here. – wobbily_col Aug 23 '16 at 14:28 @TimPietzcker - can you please explain y...
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Multiprocessing vs Threading Python [duplicate]

...n3 import multiprocessing import threading import time import sys def cpu_func(result, niters): ''' A useless CPU bound function. ''' for i in range(niters): result = (result * result * i + 2 * result * i * i + 3) % 10000000 return result class CpuThread(threading.Thre...
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How do I find the duplicates in a list and create another list with them?

...mpare each with each). For example: a = [[1], [2], [3], [1], [5], [3]] no_dupes = [x for n, x in enumerate(a) if x not in a[:n]] print no_dupes # [[1], [2], [3], [5]] dupes = [x for n, x in enumerate(a) if x in a[:n]] print dupes # [[1], [3]] ...
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Get city name using geolocation

...ake an educated guess as to which one will have the city. "administrative_area_level_1" is usually what you are looking for but sometimes locality is the city you are after. Anyhow - more details on google response types can be found here and here. Below is the code that should do the trick: &...
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Query to list all stored procedures

... As Mike stated, the best way is to use information_schema. As long as you're not in the master database, system stored procedures won't be returned. SELECT * FROM DatabaseName.INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_TYPE = 'PROCEDURE' If for some reason you had non...