Slicing data_sets, format for .append and correct indexing

Hi. First, I’m trying to get a good understanding of the syntax for .append and the correct indexing when slicing data sets. Second, I’d like to see if I can use that to eliminate a couple lines of code and/or making a new variable. I commented out the bits I’m looking at.

Here’s a data sample and the python I’m poking at.

apps_data = [['id', 'track_name', 'size_bytes', 'currency', 'price', 'rating_count_tot', 'rating_count_ver', 'user_rating', 'user_rating_ver', 'ver', 'cont_rating', 'prime_genre', 'sup_devices.num', 'ipadSc_urls.num', 'lang.num', 'vpp_lic'],
 ['284882215', 'Facebook', '389879808', 'USD', '0.0', '2974676', '212', '3.5', '3.5', '95.0', '4+', 'Social Networking', '37', '1', '29', '1'],
 ['389801252', 'Instagram', '113954816', 'USD', '0.0', '2161558', '1289', '4.5', '4.0', '10.23', '12+', 'Photo & Video', '37', '0', '29', '1'],
 ['529479190', 'Clash of Clans', '116476928', 'USD', '0.0', '2130805', '579', '4.5', '4.5', '9.24.12', '9+', 'Games', '38', '5', '18', '1'],
 ['420009108', 'Temple Run', '65921024', 'USD', '0.0', '1724546', '3842', '4.5', '4.0', '1.6.2', '9+', 'Games', '40', '5', '1', '1'],
 ['284035177', 'Pandora - Music & Radio', '130242560', 'USD', '0.0', '1126879', '3594', '4.0', '4.5', '8.4.1', '12+', 'Music', '37', '4', '1', '1']]

titles_data = [title[1] for title in apps_data[1:5]]
print(titles_data)

reversed_titles_data = []
for element in range(len(titles_data)):
    reversed_titles_data.append(titles_data[-element -1]) # First, what is the format for (titles_data[this_part and_this_part])? Where can I look up the documentation?

print(reversed_titles_data)

# Second, is there a way to make someting like this work? To avoid creating a new variable...
# other_reversed_titles_data = []
# for element in range(len(apps_data)):
#     other_reversed_titles_data.append(apps_data[-element -1])

# print(other_reversed_titles_data)

The second loop produces all the data in reverse, not just the titles.

Thanks so much. Any insight is appreciated!

Hi brucemcminn
In addition to start, end, we can define step for slicing . The syntax is
[start:end:step].

reversed_titles_data = titles_data[::-1]
print(reversed_titles_data)

The documentation can be found here(scroll down until you reach the slicing part).

other_reversed_titles_data = apps_data[::-1]
print(other_reversed_titles_data)

You can refer this article as well.

Hope this answers your query.
Thanks.