%matplotlib is a magic function in IPython. I’ll quote the relevant documentation here for you to read for convenience: IPython has a set of predefined ‘magic functions’ that you can call with a command line style syntax. There are two kinds of magics, line-oriented and cell-oriented. Line magics are prefixed with the % character and work much like … Read more
This information is available in the sys.version string in the sys module: Human readable: For further processing, use sys.version_info or sys.hexversion: To ensure a script runs with a minimal version requirement of the Python interpreter add this to your code: This compares major and minor version information. Add micro (=0, 1, etc) and even releaselevel … Read more
You can use a global variable within other functions by declaring it as global within each function that assigns a value to it: I imagine the reason for it is that, since global variables are so dangerous, Python wants to make sure that you really know that’s what you’re playing with by explicitly requiring the … Read more
I don’t know of any way to import all the functions from every submodule. Importing all the functions from a submodule is possible the way you suggested with e.g. from matplotlib.pyplot import *. Be noted of a potential problem with importing every function; you may override imported functions by defining your own functions with the same … Read more
This question already has answers here: Replacements for switch statement in Python? Is there a Python equivalent for the case statement such as the examples available in VB.NET or C#?
Other posters are probably correct…there might be spaces mixed in with your tabs. Try doing a search & replace to replace all tabs with a few spaces. Try this:
Easiest way is to use math.factorial (available in Python 2.6 and above): If you want/have to write it yourself, you can use an iterative approach: or a recursive approach: Note that the factorial function is only defined for positive integers so you should also check that n >= 0 and that isinstance(n, int). If it’s not, raise a ValueError or a TypeError respectively. math.factorial will take care of this for … Read more
For accessing the elements of a list you need to use the square brackets ([]) and not the parenthesis (()). Instead of: you need to use: And instead of: you need to use:
I am creating a program that reads a file and if the first line of the file is not blank, it reads the next four lines. Calculations are performed on those lines and then the next line is read. If that line is not empty it continues. However, I am getting this error: ValueError: invalid … Read more
in is the intended way to test for the existence of a key in a dict. If you wanted a default, you can always use dict.get(): and if you wanted to always ensure a default value for any key you can either use dict.setdefault() repeatedly or defaultdict from the collections module, like so: but in … Read more