Deletion of 5th and 7th element from a list in Python

Question

i am new to python.

Question is write a function that takes a list of 10 items and deletes 5th and 7th element.The function should convert remaining list into tuple.

I have tried by dint got output:

x = int(raw_input("Please Enter The Number: "))

items = [raw_input('Enter The List of Items: ' ) for i in range(x)]

del items[5:7]

print items

Please help me to solve this problem.

You're deleting items 6 and 7. you want `del items[4], items[6]` — Elazar, Feb 09 '15 at 11:52
possible duplicate of [How to remove an element from a list by index in Python?](http://stackoverflow.com/questions/627435/how-to-remove-an-element-from-a-list-by-index-in-python) — Joe, Feb 09 '15 at 12:06

tommy.carstensen · Answer 1 · 2015-02-09T12:10:42.740

1

You can use a list comprehension:

print([items[i] for i in range(len(items)) if i not in (4,6)])

List comprehensions are well documented on python.org. "A list comprehension consists of brackets containing an expression followed by a for clause, then zero or more for or if clauses."

The result will be a new list, so if memory matters, then simply delete the items in the right order; i.e. in reverse order:

del items[6]
del items[4]

And finally in your particular case you could have done:

del items[4:7:2]

The slice function is well documented on python.org.

edited Feb 09 '15 at 12:10

answered Feb 09 '15 at 11:53

tommy.carstensen

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You might want to explain what's going on there in the code, also code formatting helps :) – kontur Feb 09 '15 at 11:55
Thanks for suggestions @kontur. I pressed that submit button a bit fast and now I get down voted. Oh dear. – tommy.carstensen Feb 09 '15 at 11:57
Here, an upvote :) Still, some explanations on what those structures are you are using in your one-liner might help OP. – kontur Feb 09 '15 at 11:59
Thanks @kontur, I linked to the documentation and added extra solutions. – tommy.carstensen Feb 09 '15 at 12:11

score 1 · Answer 2 · answered Feb 09 '15 at 11:54

1

x = int(raw_input("Please Enter The Number: "))

items = [raw_input('Enter The List of Items: ' ) for i in range(x)]

del items[6]
del items[4]


print items

answered Feb 09 '15 at 11:54

Sailesh Kotha

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you must first del item 7 and then item 5 otherwise you del the previously 8th item! – Sebastian Stigler Feb 09 '15 at 11:55

score 1 · Answer 3 · answered Feb 09 '15 at 11:55

1

Delete items from list with

del items[x] # x - list index, starting with 0

While

del items[x:y]

will delete the slice of list, its not what you are looking for. So, just call del twice, with index needed. To create tuple from list, just use

new_var = tuple(items)

answered Feb 09 '15 at 11:55

Slam

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Good explanatory answer :) – kontur Feb 09 '15 at 11:56

Antti Haapala -- Слава Україні · Answer 4 · 2015-02-09T12:24:19.233

You were supposed to return a tuple of the sequence given with 5th and 7th removed:

def fifth_and_seventh_removed(lst):
    lst = list(lst)
    del lst[6]
    del lst[4]  # order matters!
    return tuple(lst)

If you do del lst[4] followed by del lst[6], you will remove the fifth and eighth element, clearly (the why part is left as an exercise for the reader).

Alternatively for a functional approach use enumerate, with generator expression:

def tuple_with_elements_removed(l, to_remove=(5, 7)): 
    """Return a copy of a iterable with certain elements removed
       (whose ordinals are in the to_remove); by default 
       5th and 7th elements are removed:"""

    to_remove = set(to_remove)
    return tuple(e for i, e in enumerate(l, 1) if i not in to_remove)

now,

>>> print(remove_elements(range(1, 10))
(1, 2, 3, 4, 6, 8, 9)

score 0 · Answer 5 · answered Feb 09 '15 at 12:04

Delete highest index from the list.
use tuple() to convert list to tuple.

e.g.

code:

x = int(raw_input("Please Enter The Number: "))
items = [raw_input('Enter The List of Items: ' ) for i in range(x)]
print "User Input:-", items
del items[6]
print "After deleting 7th element:-", items
del items[4]
print "After deleting 5th element:-", items
items = tuple(items)
print "Tuple:-", items

output:

:~/study$ python test.py 
Please Enter The Number: 10
Enter The List of Items: 1
Enter The List of Items: 2
Enter The List of Items: 3
Enter The List of Items: 4
Enter The List of Items: 5
Enter The List of Items: 6
Enter The List of Items: 7
Enter The List of Items: 8
Enter The List of Items: 9
Enter The List of Items: 10
User Input:- ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10']
After deleting 7th element:- ['1', '2', '3', '4', '5', '6', '8', '9', '10']
After deleting 5th element:- ['1', '2', '3', '4', '6', '8', '9', '10']
Tuple:- ('1', '2', '3', '4', '6', '8', '9', '10')

Deletion of 5th and 7th element from a list in Python

5 Answers5