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How can I default a parameter to Guid.Empty in C#?
...od is called in PHP; but only creates one object for the entire program in Python. Really, I consider this to be one of the very few design flaws of Python. I'm somewhat glad C# (and VB.Net) avoided this issue by simply disallowing new objects in default parameters... though there are times where ...
What's the best manner of implementing a social activity stream? [closed]
...for you. Have a look at getstream.io There are clients available for Node, Python, Rails and PHP.
In addition have a look at this high scalability post were we explain some of the design decisions involved:
http://highscalability.com/blog/2013/10/28/design-decisions-for-scaling-your-high-traffic-fe...
What is the best django model field to use to represent a US dollar amount?
...emodel.some_currency }}
Output:
$123.00
It has a powerful backend via python-money and it's essentially a drop-in replacement for standard decimal fields.
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Can we write our own iterator in Java?
...rray of Strings
String[] languages = new String[]{"C", "C++", "Java", "Python", "Scala"};
// create your list and hold the values using the same list implementation.
SOList<String> languagesList = new SOList<String>(languages);
System.out.println("");
// Since our c...
get list from pandas dataframe column
...u pull them out, which you can then call x.tolist() on to turn them into a Python list. Alternatively you cast it with list(x).
import pandas as pd
data_dict = {'one': pd.Series([1, 2, 3], index=['a', 'b', 'c']),
'two': pd.Series([1, 2, 3, 4], index=['a', 'b', 'c', 'd'])}
df = pd.Data...
add a string prefix to each value in a string column using Pandas
...lso yields the desired output:
col
0 stra
1 str0
If you are using Python 3.6+, you can also use f-strings:
df['col'] = df['col'].apply(lambda x: f"str{x}")
yielding the same output.
The f-string version is almost as fast as @RomanPekar's solution (python 3.6.4):
df = pd.DataFrame({'col...
What's the recommended approach to resetting migration history using Django South?
... are taking too long, this worked for me.
rm <app-dir>/migrations/*
python manage.py schemamigration <app-name> --initial
python manage.py migrate <app-name> 0001 --fake --delete-ghost-migrations
Don't forget to manually restore any dependencies on other apps by adding lines li...
When should I use @classmethod and when def method(self)?
...atic method of java or C++. ( static method is a general term I guess ;) )
Python also has @staticmethod. and difference between classmethod and staticmethod is whether you can
access to class or static variable using argument or classname itself.
class TestMethod(object):
cls_var = 1
@clas...
differentiate null=True, blank=True in django
...: CharFields can get saved as NULL in the database (translating to None in Python) if you set null=True. The docs even say to avoid setting null=True because it allows two different kinds of "blanky" values. I just tested this behaviour with Django 1.8/MySQL 5.6
– Edward D'Souz...
How to organize large R programs?
...s top-level namespace (the one that ls() shows).
I was trying to simulate Python's system, where every file is a module. That would be better to have, but this seems OK.
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