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using lodash .groupBy. how to add your own keys for grouped output?
...ame": "eddie",
"color": "green",
"age": "77"
}];
console.log(
_.chain(data)
// Group the elements of Array based on `color` property
.groupBy("color")
// `key` is group's name (color), `value` is the array of objects
.map((value, key) => ({ color: key, users: valu...
MySQL: What's the difference between float and double?
...00002 | 1.6900000000 |
This is using MySQL 6.7
Query:
SELECT
float_1 + float_2 as 'float add',
double_1 + double_2 as 'double add',
decimal_1 + decimal_2 as 'decimal add',
float_1 * float_2 as 'float multiply',
double_1 * double_2 as 'double multiply',
decimal_1 * decim...
Why does Ruby 1.9.2 remove “.” from LOAD_PATH, and what's the alternative?
...s to Ruby 1.9.2 no longer make the current directory . part of your LOAD_PATH . I have a non-trivial number of Rakefiles that assume that . is part of the LOAD_PATH , so this broke them (they reported "no such file to load" for all require statements that based off the project path). Was there...
Disable output buffering
...pper which
does a flush after every call.
class Unbuffered(object):
def __init__(self, stream):
self.stream = stream
def write(self, data):
self.stream.write(data)
self.stream.flush()
def writelines(self, datas):
self.stream.writelines(datas)
self.stream.f...
Does Python have “private” variables in classes?
... want to emulate private variables for some reason, you can always use the __ prefix from PEP 8. Python mangles the names of variables like __foo so that they're not easily visible to code outside the class that contains them (although you can get around it if you're determined enough, just like you...
Union of dict objects in Python [duplicate]
...
How is tmp = dict(y); tmp.update(x); do_something(tmp) simpler?
– Mechanical snail
Aug 7 '12 at 6:04
7
...
How to implement “select all” check box in HTML?
...: for each...in is actually valid Javascript: developer.mozilla.org/en/Core_JavaScript_1.5_Reference/… But, as porneL has pointed out, it's an obscure construct. Also, this code doesn't work in Safari 5 or Chrome 5. It works in FF 3.6, and IIRC, it worked in Safari 4. for(var i in checkboxes) chec...
What are the differences between the threading and multiprocessing modules?
...nd a thread pool like this:
with concurrent.futures.ThreadPoolExecutor(max_workers=4) as executor:
executor.submit(job, argument)
executor.map(some_function, collection_of_independent_things)
# ...
You can even get the results of those jobs and pass them on to further jobs, wait for t...
How to clear the interpreter console?
...s file in your python search path:
# wiper.py
class Wipe(object):
def __repr__(self):
return '\n'*1000
wipe = Wipe()
Then you can do this from the interpreter all you like :)
>>> from wiper import wipe
>>> wipe
>>> wipe
>>> wipe
...
Starting python debugger automatically on error
...
You can use traceback.print_exc to print the exceptions traceback. Then use sys.exc_info to extract the traceback and finally call pdb.post_mortem with that traceback
import pdb, traceback, sys
def bombs():
a = []
print a[0]
if __name__ == '...