How to select only last names?

Frequently Asked Questions Python FAQ
148

If you look at the documentation for the pop method,

Remove the item at the given position in the list, and return it. If no index is specified, a.pop() removes and returns the last item in the list.

For example,

x = [1, 4, 6, 8, 34]
y = x.pop()

print(y) # 34
print(x) # [1, 4, 6, 8]

# The popped/removed element is returned by the pop method.
# The original array is mutated.
149

One line assuming you split author_names correctly

author_last_names = [name.split(' ')[-1] for name in author_names]
150

I used both .split() and .pop() in a function to accomplish this task, I took advantage of the returning property of .pop() to store the last name. This is the function:

def last_names(authors):
last_names_list =
for author in authors:
splitted_author = author.split(" ")
last_name = splitted_author.pop()
last_names_list.append(last_name)
return last_names_list

151

Hey man, thank you so much. This was quite helpful

1 Like
152

this was the first problem I ever got stuck while learning python. it was very confusing!

153

Hereā€™s what I came up with

author_last_names = [author_names[i].split()[1] for i in range(len(author_names))]
154

Do we really need to index this stuff? The values are exposed and accessible without index reference.

>>> authors = "Audre Lorde,Gabriela Mistral,Jean Toomer,An Qi,Walt Whitman,Shel Silverstein,Carmen Boullosa,Kamala Suraiyya,Langston Hughes,Adrienne Rich,Nikki Giovanni"
>>> [x.split()[-1] for x in authors.split(',')]
['Lorde', 'Mistral', 'Toomer', 'Qi', 'Whitman', 'Silverstein', 'Boullosa', 'Suraiyya', 'Hughes', 'Rich', 'Giovanni']
>>>

Going down the rabbit holeā€¦

>>> import re
>>> authors = "Audre Lorde, Gabriela Mistral, Jean Toomer, An Qi,Walt Whitman, Shel Silverstein, Carmen Boullosa, Kamala Suraiyya, Langston Hughes, Adrienne Rich, Nikki Giovanni"
>>> [x.split()[-1] for x in re.split(r'[(,)|(,*)]', authors)]
['Lorde', 'Mistral', 'Toomer', 'Qi', 'Whitman', 'Silverstein', 'Boullosa', 'Suraiyya', 'Hughes', 'Rich', 'Giovanni']
>>>

Not that it proves anything, if in fact, nothing, itā€™s a rabbit hole. Descend at oneā€™s own peril or benefit, as it were.

My own concern was the whitespace potentially following the comma but it seems Python has worked that out and strips it from the proceeds.

>>> authors = "Audre Lorde, Gabriela Mistral, Jean Toomer, An Qi, Walt Whitman, Shel Silverstein, Carmen Boullosa, Kamala Suraiyya, Langston Hughes, Adrienne Rich, Nikki Giovanni"
>>> [x.split()[0] for x in authors.split(',')]
['Audre', 'Gabriela', 'Jean', 'An', 'Walt', 'Shel', 'Carmen', 'Kamala', 'Langston', 'Adrienne', 'Nikki']
>>>

Iā€™m blown away by having taken this long to discover it. Dang!

Going further downā€¦

By only the slightest turn of phrase we can go from a list to a set to dictionary. No magic involved, just syntax.

>>> authors = "Audre Lorde, Gabriela Mistral, Jean Toomer, An Qi, Walt Whitman, Shel Silverstein, Carmen Boullosa, Kamala Suraiyya, Langston Hughes, Adrienne Rich, Nikki Giovanni"
>>> [x.split()[0] for x in authors.split(',')]
['Audre', 'Gabriela', 'Jean', 'An', 'Walt', 'Shel', 'Carmen', 'Kamala', 'Langston', 'Adrienne', 'Nikki']
>>> [x.split()[-1] for x in authors.split(',')]
['Lorde', 'Mistral', 'Toomer', 'Qi', 'Whitman', 'Silverstein', 'Boullosa', 'Suraiyya', 'Hughes', 'Rich', 'Giovanni']
>>> [(x.split()[-1], x.split()[0]) for x in authors.split(',')]
[('Lorde', 'Audre'), ('Mistral', 'Gabriela'), ('Toomer', 'Jean'), ('Qi', 'An'), ('Whitman', 'Walt'), ('Silverstein', 'Shel'), ('Boullosa', 'Carmen'), ('Suraiyya', 'Kamala'), ('Hughes', 'Langston'), ('Rich', 'Adrienne'), ('Giovanni', 'Nikki')]
>>> {(x.split()[-1], x.split()[0]) for x in authors.split(',')}
{('Whitman', 'Walt'), ('Lorde', 'Audre'), ('Suraiyya', 'Kamala'), ('Boullosa', 'Carmen'), ('Toomer', 'Jean'), ('Qi', 'An'), ('Giovanni', 'Nikki'), ('Silverstein', 'Shel'), ('Rich', 'Adrienne'), ('Hughes', 'Langston'), ('Mistral', 'Gabriela')}
>>> {x.split()[-1]: x.split()[0] for x in authors.split(',')}
{'Lorde': 'Audre', 'Mistral': 'Gabriela', 'Toomer': 'Jean', 'Qi': 'An', 'Whitman': 'Walt', 'Silverstein': 'Shel', 'Boullosa': 'Carmen', 'Suraiyya': 'Kamala', 'Hughes': 'Langston', 'Rich': 'Adrienne', 'Giovanni': 'Nikki'}
>>>

List, Set, Dictionary. Happy trails drawing all three of these together. They make up the entire strategy of data management.

155

Youā€™re right we donā€™t really need to index it. Personally, I just like to index it whenever I loop through elements. I like to work with enhanced for loops but either way, I just wanted to make it a one-line approach and it worked!

1 Like
156

Just to share in my solution here, in case it helps any others as it stumped me for a little while too;

author_count = range(0,len(author_names))
author_last_names = []

for count in author_count:
  name = author_names[count]
  name_split = name.split()
  author_last_names.append(name_split[-1])

My goal was to try and write something that could be easily interpreted, and also theoretically expandable/could work with any size list, and would also work for names that were more than just two parts.

157

Thank you for this. Really good explanation.

158

read this thread after writing this code

authors = "Audre Lorde,Gabriela Mistral,Jean Toomer,An Qi,Walt Whitman,Shel Silverstein,Carmen Boullosa,Kamala Suraiyya,Langston Hughes,Adrienne Rich,Nikki Giovanni"
author_names = authors.split(",")
author_last = []
author_last_names = []
for i in author_names:
  author_last.append(i.split())
for i in author_last:
  author_last_names.append(i[1])
print(author_last_names)