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How do I get the directory that a program is running from?
... When I see code that looks at /proc part of me dies a little. All the world is not Linux, and even on that one platform /proc should be considered subject to change from version to version, arch to arch, etc.
– asveikau
Jan 28 '10 at 0:29
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What is the difference between shallow copy, deepcopy and normal assignment operation?
...ble towards the existing object. The docs explain the difference between shallow and deep copies:
The difference between shallow and deep copying is only relevant for
compound objects (objects that contain other objects, like lists or
class instances):
A shallow copy constructs a new...
How do I create an abstract base class in JavaScript?
...l value instead of an object so as to continue application execution, it really depends on your implementation. This, in my opinion, is the correct way to implement abstract JS "classes".
– dudewad
Jan 18 '16 at 21:36
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Converting strings to floats in a DataFrame
...newer version of pandas (0.17 and up), you can use to_numeric function. It allows you to convert the whole dataframe or just individual columns. It also gives you an ability to select how to treat stuff that can't be converted to numeric values:
import pandas as pd
s = pd.Series(['1.0', '2', -3])
p...
What does new self(); mean in PHP?
... the parent class
The first situation would look like this (I've removed all non-necessary code, for this example -- you'll have to add it back to get the singleton behavior)* :
class MyParentClass {
}
class MyChildClass extends MyParentClass {
public static function getInstance() {
...
How do you Encrypt and Decrypt a PHP String?
... You may also use GCM (which removes the need for a separate MAC). Additionally, ChaCha20 and Salsa20 (provided by libsodium) are stream ciphers and do not need special modes.
Unless you chose GCM above, you should authenticate the ciphertext with HMAC-SHA-256 (or, for the stream ciphers, Poly1305 -...
python setup.py uninstall
I have installed a python package with python setup.py install .
16 Answers
16
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SQLAlchemy default DateTime
... This isn't right. The timestamp at model load will be used for all new records rather than the time the record is added.
– SkyLeach
Feb 9 '16 at 16:18
10
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What is the difference between char, nchar, varchar, and nvarchar in SQL Server?
...torage space for number of characters you specify even if you don't use up all that space.
varchar and nvarchar are variable-length which will only use up spaces for the characters you store. It will not reserve storage like char or nchar.
nchar and nvarchar will take up twice as much storage spac...
Is there a way for multiple processes to share a listening socket?
...POSIX type OS), using fork() will cause the forked child to have copies of all the parent's file descriptors. Any that it does not close will continue to be shared, and (for example with a TCP listening socket) can be used to accept() new sockets for clients. This is how many servers, including Apac...