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Immutable vs Mutable types
... changing what the variable refers to. A mutable type can change that way, and it can also change "in place".
Here is the difference.
x = something # immutable type
print x
func(x)
print x # prints the same thing
x = something # mutable type
print x
func(x)
print x # might print something differe...
Android: Getting a file URI from a content URI?
In my app the user is to select an audio file which the app then handles. The problem is that in order for the app to do what I want it to do with the audio files, I need the URI to be in file format. When I use Android's native music player to browse for the audio file in the app, the URI is a cont...
How can I quickly sum all numbers in a file?
I have a file which contains several thousand numbers, each on it's own line:
33 Answers
...
What are the advantages of NumPy over regular Python lists?
... single-precision floats in the cells would fit in 4 MB. Access in reading and writing items is also faster with NumPy.
Maybe you don't care that much for just a million cells, but you definitely would for a billion cells -- neither approach would fit in a 32-bit architecture, but with 64-bit build...
Efficiently updating database using SQLAlchemy ORM
I'm starting a new application and looking at using an ORM -- in particular, SQLAlchemy.
6 Answers
...
Simple argparse example wanted: 1 argument, 3 results
...tiny beginner brain to grasp right now. I don't need to do math on the command line or meddle with formatting lines on the screen or change option characters. All I want to do is "If arg is A, do this, if B do that, if none of the above show help and quit" .
...
How can I view all the git repositories on my machine?
...which I can see all the git repositories that exist on my machine? Any command for that?
10 Answers
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Rails 3 execute custom sql query without a model
I need to write a standalone ruby script that is supposed to deal with database. I used code given below in rails 3
5 Answe...
How to repeat a “block” in a django template
... {% block content %}{% endblock %}
</body>
</html>
and then:
# blog.html
{% extends 'base.html' %}
{% block content %}
<h1>{% block title %}My Blog{% endblock %}</h1>
Lorem ipsum here...
{% endblock %}
and so on... Looks like DRY-compatible.
...
django: BooleanField, how to set the default value to true?
...lay. This value
is not used as a fallback if data isn't given.
And if you dig into the code of form validation process, you will find that, for each fields, form will call it's widget's value_from_datadict to get actual value, so this is the place where we can inject default value.
To d...