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How to check if a table contains an element in Lua?
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Perhaps also function keysOfSet(set) local ret={} for k,_ in pairs(set) do ret[#ret+1]=k end return ret end
– Jesse Chisholm
Apr 27 '18 at 21:40
add a comme...
Call one constructor from another
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@ivan_pozdeev: Yes, you can; use ?: or call a static method.
– SLaks
Oct 12 '14 at 1:17
3
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How do I check if a list is empty?
...al consensus seems to be that duck typing wins out (in effect, saying that __nonzero__ is the interface for testing emptiness docs.python.org/reference/datamodel.html#object.__nonzero__)
– andrew cooke
May 31 '12 at 14:50
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Can I install Python windows packages into virtualenvs?
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Yes, you can. All you need is
easy_install
binary_installer_built_with_distutils.exe
Surprised? It looks like binary installers for Windows made with distutils combine .exe with .zip into one .exe file. Change extension to .zip to see it's a valid zip fil...
Specifying an Index (Non-Unique Key) Using JPA
...Table;
@Entity
@Table(name = "region",
indexes = {@Index(name = "my_index_name", columnList="iso_code", unique = true),
@Index(name = "my_index_name2", columnList="name", unique = false)})
public class Region{
@Column(name = "iso_code", nullable = false)
priva...
Node.js / Express.js - How does app.router work?
...r middleware is given to use first.
If you do this:
app.use(express.static(__dirname + '/public'));
app.use(app.router);
Then the file on disk is served.
If you do it the other way,
app.use(app.router);
app.use(express.static(__dirname + '/public'));
Then the route handler gets the request, and "H...
How to run a python script from IDLE interactive shell?
...s.call(['python', 'helloworld.py']) # Just run the program
subprocess.check_output(['python', 'helloworld.py']) # Also gets you the stdout
With arguments:
subprocess.call(['python', 'helloworld.py', 'arg'])
Read the docs for details :-)
Tested with this basic helloworld.py:
import sys
if le...
How to pass arguments to a Button command in Tkinter?
... library functools, like this:
from functools import partial
#(...)
action_with_arg = partial(action, arg)
button = Tk.Button(master=frame, text='press', command=action_with_arg)
share
|
improve t...
Django admin: how to sort by one of the custom list_display fields that has no database field
How could I sort Customers, depending on number_of_orders they have?
3 Answers
3
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What's the algorithm to calculate aspect ratio?
...store.steampowered.com/hwsurvey, section 'Primary Display Resolution'
steam_file = './steam.txt'
# Taken from http://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/Vector_Video_Standards4.svg/750px-Vector_Video_Standards4.svg.png
accepted_ratios = ['5:4', '4:3', '3:2', '8:5', '5:3', '16:9', '17:...