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sys.argv[1] meaning in script
... prints the number of arguments, using the len function on the list.
from __future__ import print_function
import sys
print(sys.argv, len(sys.argv))
The script requires Python 2.6 or later. If you call this script print_args.py, you can invoke it with different arguments to see what happens.
>...
Django DB Settings 'Improperly Configured' Error
...--settings=mysite.settings (or whatever settings module you use)
Set DJANGO_SETTINGS_MODULE environment variable in your OS to mysite.settings
(This is removed in Django 1.6) Use setup_environ in the python interpreter:
from django.core.management import setup_environ
from mysite import settings
s...
When should I use ugettext_lazy?
I have a question about using ugettext and ugettext_lazy for translations.
I learned that in models I should use ugettext_lazy , while in views ugettext.
But are there any other places, where I should use ugettext_lazy too? What about form definitions?
Are there any performance diffrences betwe...
In Python, using argparse, allow only positive integers
...still need to define an actual method that decides this for you:
def check_positive(value):
ivalue = int(value)
if ivalue <= 0:
raise argparse.ArgumentTypeError("%s is an invalid positive int value" % value)
return ivalue
parser = argparse.ArgumentParser(...)
parser.add_argu...
Quick easy way to migrate SQLite3 to MySQL? [closed]
...two file formats:
The lines starting with:
BEGIN TRANSACTION
COMMIT
sqlite_sequence
CREATE UNIQUE INDEX
are not used in MySQL
SQLite uses CREATE TABLE/INSERT INTO "table_name" and MySQL uses CREATE TABLE/INSERT INTO table_name
MySQL doesn't use quotes inside the schema definition
MySQL uses singl...
Why is there no xrange function in Python3?
...tion has nothing to do with it. (Not surprising, as a one-time call to the __iter__ slot isn't likely to be visible among 10000000 calls to whatever happens in the loop, but someone brought it up as a possibility.)
But it's only 30% slower. How did the OP get 2x as slow? Well, if I repeat the same ...
Adding new column to existing DataFrame in Python pandas
...17438 0.847941 0.034235 -0.448948 2.228131
>>> p.version.short_version
'0.16.1'
The SettingWithCopyWarning aims to inform of a possibly invalid assignment on a copy of the Dataframe. It doesn't necessarily say you did it wrong (it can trigger false positives) but from 0.13.0 it let yo...
Markdown open a new window link [duplicate]
...always use HTML inside markdown:
<a href="http://example.com/" target="_blank">example</a>
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How do you build a Singleton in Dart?
...t's easy to build a singleton:
class Singleton {
static final Singleton _singleton = Singleton._internal();
factory Singleton() {
return _singleton;
}
Singleton._internal();
}
You can construct it like this
main() {
var s1 = Singleton();
var s2 = Singleton();
print(identical(...
Converting strings to floats in a DataFrame
...
NOTE: pd.convert_objects has now been deprecated. You should use pd.Series.astype(float) or pd.to_numeric as described in other
answers.
This is available in 0.11. Forces conversion (or set's to nan)
This will work even when astype will ...