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How to remove a key from a Python dictionary?
...t.pop():
my_dict.pop('key', None)
This will return my_dict[key] if key exists in the dictionary, and None otherwise. If the second parameter is not specified (ie. my_dict.pop('key')) and key does not exist, a KeyError is raised.
To delete a key that is guaranteed to exist, you can also use
del ...
How to find all tables that have foreign keys that reference particular table.column and have values
... primary key is referenced in several other tables as a foreign key. For example:
7 Answers
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Changing MongoDB data store directory
... default /data/db
dbpath = /usr/local/var/mongodb
The official 10gen Linux packages (Ubuntu/Debian or CentOS/Fedora) ship with a basic configuration file which is placed in /etc/mongodb.conf, and the MongoDB service reads this when it starts up. You could make your change here.
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Deleting all pending tasks in celery / rabbitmq
...s with a redis backend. Best method I found was redis-cli KEYS "celery*" | xargs redis-cli DEL which worked for me. This will wipe out all tasks stored on the redis backend you're using.
– Melignus
Aug 28 '13 at 17:22
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IE9 jQuery AJAX with CORS returns “Access is denied”
The following works in all browsers except IE (I'm testing in IE 9).
12 Answers
12
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JavaScript object: access variable property by name as string [duplicate]
...mns['right'];
This is equal to dot notation, var side = columns.right;, except the fact that right could also come from a variable, function return value, etc., when using bracket notation.
If you NEED a function for it, here it is:
function read_prop(obj, prop) {
return obj[prop];
}
To ...
How to print a int64_t type in C
...ttypes.h>
uint64_t t;
printf("%" PRIu64 "\n", t);
you can also use PRIx64 to print in hexadecimal.
cppreference.com has a full listing of available macros for all types including intptr_t (PRIxPTR). There are separate macros for scanf, like SCNd64.
A typical definition of PRIu16 would be "...
Copy/duplicate database without using mysqldump
...e the target database using MySQLAdmin or your preferred method. In this example, db2 is the target database, where the source database db1 will be copied.
Execute the following statement on a command line:
mysqldump -h [server] -u [user] -p[password] db1 | mysql -h [server] -u [user] -p[password...
Comparing two NumPy arrays for equality, element-wise
...rt numpy as np H = 1/np.sqrt(2)*np.array([[1, 1], [1, -1]]) #hadamard matrix np.array_equal(H.dot(H.T.conj()), np.eye(len(H))) # checking if H is an unitary matrix or not H is an unitary matrix, so H x H.T.conj is an identity matrix. But np.array_equal returns False
– Dex
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How to convert a PIL Image into a numpy array?
...PIL image object back and forth to a numpy array so I can do some faster pixel by pixel transformations than PIL's PixelAccess object would allow. I've figured out how to place the pixel information in a useful 3D numpy array by way of:
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