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How to export table as CSV with headings on Postgresql?
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COPY products_273 TO '/tmp/products_199.csv' WITH (FORMAT CSV, HEADER);
as described in the manual.
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List comprehension: Returning two (or more) items for each item
...bda x: x + 2
>>> g = lambda x: x ** 2
>>> list(chain.from_iterable((f(x), g(x)) for x in range(3)))
[2, 0, 3, 1, 4, 4]
Timings:
from timeit import timeit
f = lambda x: x + 2
g = lambda x: x ** 2
def fg(x):
yield f(x)
yield g(x)
print timeit(stmt='list(chain.from_itera...
Undoing a 'git push'
... highly dangerous if you are working in a shared repo. As a best practice, all commits pushed to a remote repo that is shared should be considered 'immutable'. Use 'git revert' instead: kernel.org/pub/software/scm/git/docs/…
– Saboosh
Jan 13 '12 at 20:47
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YouTube API to fetch all videos on a channel
...rly because it only spends 2 quota points instead of 100 (that the search call would spend).
– JP de la Torre
Nov 12 '16 at 10:28
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What does it mean for a data structure to be “intrusive”?
...to know about the list it is in, and inform it of changes.
ORM-systems usually revolve around intrusive data structures, to minimize iteration over large lists of objects. For instance, if you retrieve a list of all the employees in the database, then change the name of one of them, and want to sav...
How to find all occurrences of a substring?
Python has string.find() and string.rfind() to get the index of a substring in a string.
20 Answers
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How do you sort a list in Jinja2?
...ilter allows you to specify an attribute to sort by:
{% for movie in movie_list|sort(attribute='rating') %}
See http://jinja.pocoo.org/docs/templates/#sort
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Regular expression to match numbers with or without commas and decimals in text
...t by giving everybody what they Googled for:
#ALL THESE REQUIRE THE WHOLE STRING TO BE A NUMBER
#For numbers embedded in sentences, see discussion below
#### NUMBERS AND DECIMALS ONLY ####
#No commas allowed
#Pass: (1000.0), (001), (.001)
#Fail: (1,000.0)
^\d*\.?\d+$
#No commas allowed
#Can't sta...
Angular JS break ForEach
...r for it does not break the forEach loop. It is merly a way to not execute all logic inside the loop.
– Nebulosar
Apr 8 at 13:42
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Applying a function to every row of a table using dplyr?
...it reflects the fact that when you're doing row wise operations you're actually working with tuples from a list of vectors (the columns in a dataframe).
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