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Does the join order matter in SQL?
Disregarding performance, will I get the same result from query A and B below? How about C and D?
4 Answers
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Understand homebrew and keg-only dependencies
I've recently started using homebrew, and I'm a bit confused as to what happens when I brew something onto my system, but its brewed dependencies are keg-only, meaning that they are linked under /usr/local .
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Pandas DataFrame column to list [duplicate]
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You can use the Series.to_list method.
For example:
import pandas as pd
df = pd.DataFrame({'a': [1, 3, 5, 7, 4, 5, 6, 4, 7, 8, 9],
'b': [3, 5, 6, 2, 4, 6, 7, 8, 7, 8, 9]})
print(df['a'].to_list())
Output:
[1, 3, 5, 7, 4, 5, 6, 4, 7, 8, 9]
To drop duplicates y...
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...
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...
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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How to implement WiX installer upgrade?
...omatic upgrades. It prevents downgrades, giving a localised error message, and also prevents upgrading an already existing identical version (i.e. only lower versions are upgraded):
<MajorUpgrade
AllowDowngrades="no" DowngradeErrorMessage="!(loc.NewerVersionInstalled)"
AllowSameVersionUp...
Detect changes in the DOM
...need to create your own domChanged API - with a function or custom event - and trigger/call it everywhere you modify things.
The DOM Level-2 has Mutation event types, but older version of IE don't support it. Note that the mutation events are deprecated in the DOM3 Events spec and have a performan...
How to select Python version in PyCharm?
I have PyCharm 1.5.4 and have used the "Open Directory" option to open the contents of a folder in the IDE.
6 Answers
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