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Visibility of global variables in imported modules
...a Python script. I'll do my best to describe the error, why I run into it, and why I'm tying this particular approach to solve my problem (which I will describe in a second):
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Gem::LoadError for mysql2 gem, but it's already in Gemfile
...his question by me 8 September 2015 so use the above line in your Gem file and run:
bundle install
You should be good to go
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Regular expression to get a string between two strings in Javascript
...ot consume any input. It is a zero-width assertion (as are boundary checks and lookbehinds).
You want a regular match here, to consume the cow portion. To capture the portion in between, you use a capturing group (just put the portion of pattern you want to capture inside parenthesis):
cow(.*)mi...
git: How to ignore all present untracked files?
Is there a handy way to ignore all untracked files and folders in a git repository?
(I know about the .gitignore .)
8 An...
How do you Encrypt and Decrypt a PHP String?
...
Before you do anything further, seek to understand the difference between encryption and authentication, and why you probably want authenticated encryption rather than just encryption.
To implement authenticated encryption, you want to Encrypt then MAC. The order of encry...
Using curl POST with variables defined in bash script functions
...script. This saves you from all sort of headaches concerning shell quoting and makes it easier to read an maintain the script than feeding the post data on curl's invocation line as in your attempt:
generate_post_data()
{
cat <<EOF
{
"account": {
"email": "$email",
"screenName": "...
Python Pandas: Get index of rows which column matches certain value
...ue
50 True
[3 rows x 1 columns]
If you have a boolean array, mask, and need ordinal index values, you can compute them using np.flatnonzero:
In [110]: np.flatnonzero(df['BoolCol'])
Out[112]: array([0, 3, 4])
Use df.iloc to select rows by ordinal index:
In [113]: df.iloc[np.flatnonzero(df...
What is the best algorithm for overriding GetHashCode?
...he implementation given in Josh Bloch's fabulous Effective Java. It's fast and creates a pretty good hash which is unlikely to cause collisions. Pick two different prime numbers, e.g. 17 and 23, and do:
public override int GetHashCode()
{
unchecked // Overflow is fine, just wrap
{
i...
Javascript when to use prototypes
I'd like to understand when it is appropriate to use prototype methods in js. Should they always be used? Or are there cases where using them is not preferred and/or incurs a performance penalty?
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Finding all possible combinations of numbers to reach a given sum
...])=15
This type of algorithms are very well explained in the following Standford's Abstract Programming lecture - this video is very recommendable to understand how recursion works to generate permutations of solutions.
Edit
The above as a generator function, making it a bit more useful. Require...