How to create an if statement for elements within a list?

Question

I am wondering how I can create an if statement that does something to a list as long as there is at least one value in the list that meets the if statement's requirements.

For example, given a list

x=[1,2,3,4,5,6,7,8,9]
y=[1,2,3,4]
z=[1,2,3,8]

I want to create an if statement where if the list contains elements whose values are between 5 and 10, then the list appends ***.

Meaning, after the if statement, the results would be

x=[1,2,3,4,5,6,7,8,9,***]
y=[1,2,3,4]
z=[1,2,3,8,***]

since both x and z contains elements that are between 5 and 10, they receive the ***.

Perhaps this will help: https://stackoverflow.com/q/19389490/4996248 — John Coleman, Jan 18 '19 at 19:55
This sounds like homework. At the very least you should show us what you have tried — IanQ, Jan 18 '19 at 19:55
You should loop over the list (or use a list comprehension) to verify that the condition is satisfied and in case do what you want to do. — Valentino, Jan 18 '19 at 19:55

score 4 · Answer 1 · edited Jan 18 '19 at 20:14

4

You could do this. Test if any of the elements match your condition using a generator expression and the any() function.

x = [1,2,3,4] #two lists for testing
y = [5]       

if any(5 <= i <= 10 for i in x):
        x.append("***")

if any(5 <= i <= 10 for i in y):
        y.append("***")

print(x,y)

Output:

[1, 2, 3, 4] [5, '***']

edited Jan 18 '19 at 20:14

John Kugelman

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answered Jan 18 '19 at 19:58

KuboMD

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okovko · Accepted Answer · 2019-01-18T20:05:41.457

2

The most succinct way to do this in Python 3 is to use a generator expression:

if any(5 < x < 10 for x in lst):
  lst.append('***')

Here is a working example.

Edit: That syntax is kind of mind blowing, thanks for the edit and the comment.

edited Jan 18 '19 at 20:05

answered Jan 18 '19 at 19:58

okovko

1,851
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Dito Khelaia · Answer 3 · 2019-01-19T16:20:04.583

-1

i=0
while i<len(x):
  if x[i]>5 and x[i]<10: #if any item of list is between 5 and 10 break loop
    break
  i+=1

if i<len(x): #check if i less than len(x) this means that loop 'broken' until the end
  x.append('***')

edited Jan 19 '19 at 16:20

answered Jan 18 '19 at 19:58

Dito Khelaia

138
1
11

You should try to do this without `while`, iterator and `break`. Your code is too complex. Do not forget the Zen of python and Keep It Simple Stupid (KISS). – Dorian Turba Jan 18 '19 at 20:09

How to create an if statement for elements within a list?

3 Answers3