This page will go through how to repeat a loop in python n times. This will be shown with both a For loop as well as a While loop.
Whilst looping is a great thing, and a first step in many languages. Please consider switching to matrix operations once the dataset gets a lot bigger as that will have a dramatic impact on performance when working with thousands, or millions of rows. For example 1 line of code to add a "column calculation" versus looping through the entire matrix.
Loops can be divided in to two types of loops: For Loops or While Loops. For Loops are definitely the ones I use the most. Whilst creating While loops can be a good thing, sometimes it can also get your code into an annoying endless circle as it is basically just a 'For loop' to infinity.
For Loops examples
Below we show a simple For loop that is repeated 10 times in two different ways since python's range syntax starts with 0.
# Looping 0 to 9, which is 10 times. for x in range(10): print(x)
The "Range" syntax above is useful for looping to a number or between certain numbers. In python, the first index is 0. which is recurring for many other python syntaxes. The range syntax works like the following.
class range(start, stop[, step])
This means that we can use the second class option above to write the python statement so that our loop starts at 1 and goes to 10. Note that our first loop stopped at 9 so in order for our loop to stop and include 10 we need to change the stop number to 11 like below.
# Looping 1 to 10, which is 10 times. for x in range(1,11): print(x)
If we want to repeat a loop 10 times with a While syntax, we don't need to use the "Range syntax". We can simply use a variable "i" in this case for which we increase (or decrease for that matter) the value for each iteration.
# need to increment i with 1 for each loop. # otherwise this loop will continue forever. # increment of i could also have been written as i = i + 1. i = 1 while i < 10: print(i) i += 1
Learn more about Python loops in my complete guide here:
Learn more about VBA here for all my posts: https://www.pls-fix-thx.com/vba
Learn more about Python here for all my posts: https://www.pls-fix-thx.com/python
If you have found this article or website helpful. Please show your support by visiting the shop below.