How do you add elements of a list together to make a string (python)

Question

My ultimate goal is to make a function that takes a number and returns the prime factorization, which I have achieved. Currently, it returns a list in the form of [number,power] with every prime to every power. What I want to do is take that list and turn it into a bunch of strings that say "the prime factors of this number are: number to power, number to power," etc. Also, unrelated question: how do I get the python error screen to stay. I've resorted to creating a batch file to auto-start the python file so I can take a screenshot of it and read the error, because it instantly goes away.

Given `items` as a `list()`, you can use list comprehension: `''.join([str(item) for item in items])` — Mr. Polywhirl, Oct 29 '14 at 23:25
thats actually a generator expression... minor nitpick but they are different — Joran Beasley, Oct 29 '14 at 23:25
Here are multiple answers for you http://stackoverflow.com/questions/5850986/joining-elements-of-a-list-python — PureData1, Oct 29 '14 at 23:30

score 0 · Accepted Answer · answered Oct 29 '14 at 23:25

0

Python provides some pretty nice ways of doing this. For example:

>>> a = [[2,3], [4,5]]
>>> ", ".join("{0} to {1}".format(n, p) for n, p in a)
'2 to 3, 4 to 5'

This is called a generator expression.

answered Oct 29 '14 at 23:25

Greg Hewgill

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score 0 · Answer 2 · edited Mar 26 '16 at 15:41

If you right click on the python file, click edit with IDLE, and then click f5 to run your program, something like this would appear.

Python 3.5.1 (v3.5.1:37a07cee5969, Dec  6 2015, 01:38:48) [MSC v.1900 32  bit (Intel)] on win32
Type "copyright", "credits" or "license()" for more information.

This will allow the code to run in a window known a Python Shell, where the error message would stay.

How do you add elements of a list together to make a string (python)

2 Answers2