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Double vs single quotes
I'm really new to Ruby and I'm trying to understand if there's a specific time when I should use "" vs '' .
8 Answers
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Why is string concatenation faster than array join?
...owsers have also optimized string concatenation, so Safari, Opera, Chrome, and Internet Explorer 8 also show better performance using the plus operator. Internet Explorer prior to version 8 didn’t have such an optimization, and so the array technique is always faster than the plus operator.
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psql: FATAL: Peer authentication failed for user “dev”
...nfig files, especially when you don't have a clue about what you are doing and just following SO answer to solve your problem.
– borisano
Nov 24 '15 at 15:07
1
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In Python, how do I iterate over a dictionary in sorted key order?
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This is not obvious. In fact, items() creates a list and therefore uses memory, whereas iteritems() essentially does not use memory. What to use mostly depend on the size of the dictionary. Furthermore, the automatic Python 2 to Python 3 conversion tool (2to3) automatically tak...
How can I parse a YAML file in Python
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The easiest and purest method without relying on C headers is PyYaml (documentation), which can be installed via pip install pyyaml:
#!/usr/bin/env python
import yaml
with open("example.yaml", 'r') as stream:
try:
print(yam...
How to prune local tracking branches that do not exist on remote anymore
...es.
This line should do the trick (requires bash or zsh, won't work with standard Bourne shell):
git branch -r | awk '{print $1}' | egrep -v -f /dev/fd/0 <(git branch -vv | grep origin) | awk '{print $1}' | xargs git branch -d
This string gets the list of remote branches and passes it into egrep...
Find() vs. Where().FirstOrDefault()
I often see people using Where.FirstOrDefault() to do a search and grab the first element. Why not just use Find() ? Is there an advantage to the other? I couldn't tell a difference.
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Java ArrayList copy
... l1 of size 10. I assign l1 to new list reference type l2 . Will l1 and l2 point to same ArrayList object? Or is a copy of the ArrayList object assigned to l2 ?
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redirect COPY of stdout to log file from within bash script itself
...ptured - i.e. your
# log file would not contain any error messages.
# SEE (and upvote) the answer by Adam Spiers, which keeps STDERR
# as a separate stream - I did not want to steal from him by simply
# adding his answer to mine.
exec 2>&1
echo "foo"
echo "bar" >&2
Note that this is...
Can I serve multiple clients using just Flask app.run() as standalone?
...h Apache or other web servers. But, I was thinking of running Flask as a standalone server serving multiple clients simultaneously.
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