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How can I use pickle to save a dict?
...ickle', 'wb') as handle:
pickle.dump(a, handle, protocol=pickle.HIGHEST_PROTOCOL)
with open('filename.pickle', 'rb') as handle:
b = pickle.load(handle)
print a == b
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How to find list intersection?
...
Make a set out of the larger one:
_auxset = set(a)
Then,
c = [x for x in b if x in _auxset]
will do what you want (preserving b's ordering, not a's -- can't necessarily preserve both) and do it fast. (Using if x in a as the condition in the list compreh...
Flask-SQLalchemy update a row's information
...itself. Then, db.session.commit().
For example:
admin = User.query.filter_by(username='admin').first()
admin.email = 'my_new_email@example.com'
db.session.commit()
user = User.query.get(5)
user.name = 'New Name'
db.session.commit()
Flask-SQLAlchemy is based on SQLAlchemy, so be sure to check ou...
GraphViz - How to connect subgraphs?
...luster, that can be linked to even if the cluster is empty otherwise. DUMMY_0 [shape=point style=invis]
– DevSolar
Jun 25 '12 at 7:36
2
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Calling Objective-C method from C++ member function?
...hat C++ class a objective-C function [context renderbufferStorage:GL_RENDERBUFFER fromDrawable:(CAEAGLLayer*)self.layer]; which I cannot do in C++ syntax.
...
Disable assertions in Python
...umentation:
An assert statement like this:
assert expression #, optional_message
Is equivalent to
if __debug__:
if not expression: raise AssertionError #(optional_message)
And,
the built-in variable __debug__ is True under normal circumstances, False when optimization is requested...
“Pretty” Continuous Integration for Python
...h a hudson config execute script like: /var/lib/hudson/venv/main/bin/hudson_script.py -w $WORKSPACE -p my.package -v $BUILD_NUMBER, just put in **/coverage.xml, pylint.txt and nosetests.xml in the config bits:
#!/var/lib/hudson/venv/main/bin/python
import os
import re
import subprocess
import loggi...
What's the cleanest way of applying map() to a dictionary in Swift?
...
Swift 4+
Good news! Swift 4 includes a mapValues(_:) method which constructs a copy of a dictionary with the same keys, but different values. It also includes a filter(_:) overload which returns a Dictionary, and init(uniqueKeysWithValues:) and init(_:uniquingKeysWith:) ini...
Comma in C/C++ macro
...ose the macro argument in parentheses:
FOO((std::map<int, int>), map_var);
The problem is then that the parameter remains parenthesized inside the macro expansion, which prevents it being read as a type in most contexts.
A nice trick to workaround this is that in C++, you can extract a typ...
Structure padding and packing
...It inserts the following "gaps" into your first structure:
struct mystruct_A {
char a;
char gap_0[3]; /* inserted by compiler: for alignment of b */
int b;
char c;
char gap_1[3]; /* -"-: for alignment of the whole struct in an array */
} x;
Packing, on the other hand prevents ...