How do I get the number of elements in a list in Python?
How do I get the number of elements in the list items?
python
Can you monkey patch methods on core types in Python?
Ruby can add methods to the Number class and other core types to get effects like this:
Basics of recursion in Python
“Write a recursive function, “listSum” that takes a list of integers and returns the sum of all integers in the list”.
Can I add custom methods/attributes to built-in Python types?
For example—say I want to add a helloWorld() method to Python’s dict type. Can I do this?
When do I need to call mainloop in a Tkinter application?
Every tkinter tutorial I have seen claims that tkinter.mainloop must be called for windows to be drawn and events to be processed, and they always call this function, even in hello world programs. However, when I try these out in the interactive shell, windows are drawn correctly without having to call mainloop. This example of embedding matplotlib graphics in tkinter produces a relatively complex application, with buttons for panning, zooming and resizing a plot within a tkinter window, and again, this all works if you remove the call to mainloop and run the code in the interactive shell. Of course, if I run the script (with mainloop removed) outside the interactive shell, the program ends too quickly to see what happens, but if I add a call to input to hold the program open everything works correctly (I’m running python 3.2.2 on linux).
Get a list from Pandas DataFrame column headers
I want to get a list of the column headers from a Pandas DataFrame. The DataFrame will come from user input, so I won’t know how many columns there will be or what they will be called.
Passing values in Python
Python passes references-to-objects by
value (like Java), and everything in
Python is an object. This sounds
simple, but then you will notice that
some data types seem to exhibit
pass-by-value characteristics, while
others seem to act like
pass-by-reference… what’s the deal?
Why can’t non-default arguments follow default arguments?
Why does this piece of code throw a SyntaxError?
How do I create a namespace package in Python?
In Python, a namespace package allows you to spread Python code among several projects. This is useful when you want to release related libraries as separate downloads. For example, with the directories Package-1 and Package-2 in PYTHONPATH,
How do I convert a pandas Series or index to a Numpy array?
We haven’t removed or deprecated Series.values or
DataFrame.values, but we highly recommend and using .array or
.to_numpy() instead.