CODEWITHSUNDEEP
pythonpython-3.xlist
nishikant gurav
nishikant gurav

Reputation: 47

How to reverse a list containing elements as strings starting with uppercase letter followed by lowercase letters

def combine_lists(list1, list2):
  # Generate a new list containing the elements of list2
  # Followed by the elements of list1 in reverse order
  list3=list2.extend(list1.reverse())
  return list3


Jamies_list = ["Alice", "Cindy", "Bobby", "Jan", "Peter"]                     
Drews_list = ["Mike", "Carol", "Greg", "Marcia"]

print(combine_lists(Jamies_list, Drews_list))

Upvotes: 1

Views: 5866

Answers (8)

Mawloud Boulkheir
Mawloud Boulkheir

Reputation: 1

def combine_lists(list1, list2):
    Jamies_list.reverse()
    final_list = Drews_list + Jamies_list
    return final_list
Jamies_list = ["Alice", "Cindy", "Bobby", "Jan", "Peter"]
Drews_list = ["Mike", "Carol", "Greg", "Marcia"]
print(combine_lists(Jamies_list, Drews_list))

Upvotes: 0

Alex
Alex

Reputation: 13

I used the negative index to append the last element of list1 (i.e. Jamies_list) to list2 (i.e. Drews_list).

def combine_lists(list1, list2):
    for n in range(1, len(list1)+1):
        list2.append(list1[-n])
    return list2

Jamies_list = ["Alice", "Cindy", "Bobby", "Jan", "Peter"]
Drews_list = ["Mike", "Carol", "Greg", "Marcia"]
print(combine_lists(Jamies_list, Drews_list))

Upvotes: 0

ma cameron
ma cameron

Reputation: 1

Try this.

def combine_lists(list1, list2):
  # Generate a new list containing the elements of list2
  # Followed by the elements of list1 in reverse order
  list1.reverse()
  return(list2 + list1)

Jamies_list = ["Alice", "Cindy", "Bobby", "Jan", "Peter"]
Drews_list = ["Mike", "Carol", "Greg", "Marcia"]

print(combine_lists(Drews_list, Jamies_list))

Upvotes: 0

waithira
waithira

Reputation: 340

def combine_lists(list1, list2):
    list1.reverse()
    for list in list1:
        list2.append(list)
    return list2
Jamies_list = ["Alice", "Cindy", "Bobby", "Jan", "Peter"]
Drews_list = ["Mike", "Carol", "Greg", "Marcia"]

print(combine_lists(Jamies_list, Drews_list))

Upvotes: 0

Meet Sinojia
Meet Sinojia

Reputation: 131

As others have already explained, reverse() and extend() methods are in-place and return None.

If you still want to use extend() and reverse() methods, then you can do it like this:

def combine_lists(list1, list2):
  # Generate a new list containing the elements of list2
  # Followed by the elements of list1 in reverse order
  list3 = list1[:]
  list4 = list2[:]

  list3.reverse()
  list4.extend(list3)
  return list4


Jamies_list = ["Alice", "Cindy", "Bobby", "Jan", "Peter"]                     
Drews_list = ["Mike", "Carol", "Greg", "Marcia"]

print(combine_lists(Jamies_list, Drews_list))

If you don't mind changing list1 and list2 in the function, then you can skip copying list1 and list2 into list3 and list4 and directly do:

list1.reverse()
list2.extend(list1)
return list2

Upvotes: 0

Sankar
Sankar

Reputation: 586

See if this is what you are looking for :

>>> Jamies_list = ["Alice", "Cindy", "Bobby", "Jan", "Peter"]
>>> Drews_list = ["Mike", "Carol", "Greg", "Marcia"]
>>>
>>> Drews_list + Jamies_list[::-1]
['Mike', 'Carol', 'Greg', 'Marcia', 'Peter', 'Jan', 'Bobby', 'Cindy', 'Alice']

Upvotes: 3

Ch3steR
Ch3steR

Reputation: 20669

Both .reverse and .extend return None and mutate list in-palce.

Try this.

def combine_lists(list1, list2):
  # Generate a new list containing the elements of list2
  # Followed by the elements of list1 in reverse order
  return list1+list2[::-1]

And for reversing you try any of these reversed(list2) or [::-1] these methods do not mutate list in-place. Note : reversed(list2) gives an iterator

Upvotes: 0

Relandom
Relandom

Reputation: 1039

def combine_lists(list1, list2):
  # Generate a new list containing the elements of list2
  # Followed by the elements of list1 in reverse order
  buf = list2[:] # or list2.copy()
  buf.extend(reversed(list1))
  return buf


Jamies_list = ["Alice", "Cindy", "Bobby", "Jan", "Peter"]                     
Drews_list = ["Mike", "Carol", "Greg", "Marcia"]

print(combine_lists(Jamies_list, Drews_list))

extend method for list modify current list but does not return anything, so your expression: list3=list2.extend(list1.reverse()) assaign to list3 value None

Same about reverse. It modifies current list, but return None. You can replace it with reverse(list) method.

Upvotes: 0

Related Questions