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What is the difference between join and merge in Pandas?
...andas as pd
left = pd.DataFrame({'key': ['foo', 'bar'], 'val': [1, 2]}).set_index('key')
right = pd.DataFrame({'key': ['foo', 'bar'], 'val': [4, 5]}).set_index('key')
left.join(right, lsuffix='_l', rsuffix='_r')
val_l val_r
key
foo 1 4
bar 2 5
The same functi...
How to return a value from __init__ in Python?
I have a class with an __init__ function.
10 Answers
10
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Capturing Groups From a Grep RegEx
...e using Bash, you don't even have to use grep:
files="*.jpg"
regex="[0-9]+_([a-z]+)_[0-9a-z]*"
for f in $files # unquoted in order to allow the glob to expand
do
if [[ $f =~ $regex ]]
then
name="${BASH_REMATCH[1]}"
echo "${name}.jpg" # concatenate strings
name=...
Using the Underscore module with Node.js
...ms that the first time I use a function from Underscore, it overwrites the _ object with the result of my function call. Anyone know what's going on? For example, here is a session from the node.js REPL:
...
Python argparse mutual exclusive group
...
add_mutually_exclusive_group doesn't make an entire group mutually exclusive. It makes options within the group mutually exclusive.
What you're looking for is subcommands. Instead of prog [ -a xxxx | [-b yyy -c zzz]], you'd hav...
Default filter in Django admin
...ch has three values: activate , pending and rejected . When I use list_filter in Django admin, the filter is by default set to 'All' but I want to set it to pending by default.
...
How do I migrate a model out of one django app and into a new one?
...on and specific:
myproject/
|-- common
| |-- migrations
| | |-- 0001_initial.py
| | `-- 0002_create_cat.py
| `-- models.py
`-- specific
|-- migrations
| |-- 0001_initial.py
| `-- 0002_create_dog.py
`-- models.py
Now we want to move model common.models.cat to specif...
Formatting numbers (decimal places, thousands separators, etc) with CSS
....
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/toLocaleString
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Two way/reverse map [duplicate]
...ic that you want. Here's a basic example:
class TwoWayDict(dict):
def __setitem__(self, key, value):
# Remove any previous connections with these values
if key in self:
del self[key]
if value in self:
del self[value]
dict.__setitem__(self,...
How many GCC optimization levels are there?
...lear on the man page.
We shall conclude that:
anything above -O3 up to INT_MAX is the same as -O3, but that could easily change in the future, so don't rely on it.
GCC 5.1 runs undefined behavior if you enter integers larger than INT_MAX.
the argument can only have digits, or it fails gracefully. I...