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MySQL Creating tables with Foreign Keys giving errno: 150
I am trying to create a table in MySQL with two foreign keys, which reference the primary keys in 2 other tables, but I am getting an errno: 150 error and it will not create the table.
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How do I correctly clean up a Python object?
__del__(self) above fails with an AttributeError exception. I understand Python doesn't guarantee the existence of "global variables" (member data in this context?) when __del__() is invoked. If that is the case and this is the reason for the exception, how do I make sure the object destructs...
Get last dirname/filename in a file path argument in Bash
...ject to the directory where it is hosted on the server. However I need to be able to read only the last directory in the directory string passed to the script in order to checkout to the same sub-directory where our projects are hosted.
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Node.js spawn child process and get terminal output live
...s 'hi', sleeps for 1 second, and so on and so forth. Now I thought I would be able to tackle this problem with this model.
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Python super() raises TypeError
...erates on new-style classes, which in the 2.x series means extending from object:
>>> class X(object):
def a(self):
print 'a'
>>> class Y(X):
def a(self):
super(Y, self).a()
print 'b'
>>> c = Y()
>>> c.a()
a
b...
How to explain callbacks in plain english? How are they different from calling one function from ano
How to explain callbacks in plain English? How are they different from calling one function from another function taking some context from the calling function? How can their power be explained to a novice programmer?
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Space between two rows in a table?
Is this possible via CSS?
25 Answers
25
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Vim: Creating parent directories on save
If I invoke vim foo/bar/somefile but foo/bar don't already exist, Vim refuses to save.
6 Answers
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Convert Python dictionary to JSON array
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If you are fine with non-printable symbols in your json, then add ensure_ascii=False to dumps call.
>>> json.dumps(your_data, ensure_ascii=False)
If ensure_ascii is false, then the return value will be a
unicode instance subject to normal ...
How to retrieve an element from a set without removing it?
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Two options that don't require copying the whole set:
for e in s:
break
# e is now an element from s
Or...
e = next(iter(s))
But in general, sets don't support indexing or slicing.
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