Parsing a pretty printed table into Python objects [closed]

Question

Suppose there is a String called likes_and_dislikes, formatted visually as a table like that as shown below.

How can I parse the string and return a list of tuples with likes and dislikes. Also the top header(likes, dislikes) has to be removed from list of tuples.

likes_and_dislikes="""

+------------------------------------+-----------------------------------+
| likes                              | dislikes                          |
+------------------------------------+-----------------------------------+
| Meritocracy                        | Favoritism, ass-kissing, politics |
+------------------------------------+-----------------------------------+
| Healthy debates and collaboration  | Ego-driven rhetoric, drama and FUD|
|                                    | to get one's way                  |
+------------------------------------+-----------------------------------+
| Autonomy given by confident leaders| Micro-management by insecure      |
| capable of attracting top-tier     | managers compensating for a weak, |
| talent                             | immature team                     |
+------------------------------------+-----------------------------------+  """

Answer 1

The key here is to examine the table thoroughly and understand what you are trying to pull out.

First of all, parsing strings like this is generally easier when done line-by-line, so you need to split based on the table rows and then parse columns based on that. We do this primarily because the likes and dislikes span across lines.

1. Getting each row

We don't know how wide the table might be so we use regular expressions to break up our table like so:

pairs = re.split("\+-*\+-*\+\n?",likes_and_dislikes)[2:-1] #Drop the header and the tail

This gives us an array that correesponds to our multiline rows. The array slicing at the end removes the header and any trailing whitespace that we don't want to process. However, we still have the problem of pulling together strings that span multiple lines in a cell.

2. Finding a like and dislike

If we iterate through this array of rows, we know each row has a like and a dislike that spans an unknown array of lines. We initialise this like and dislike each as an array to make concatentation quicker at the end.

for p in pairs:
  like,dislike = [],[]

3. Dealing with each line

With our row, we need to split it based on newlines, then split based on the pipes (|).

  for l in p.split('\n'):
    pair = l.split('|')

4. Pulling out each like and dislike

If the pair we are given has more than one value, then there must be a pair of likes or dislikes for us to capture. So append it to our like and dislike array - not the likes or dislikes as these hold our finally formatted strings. We also should perform a strip on these to remove any trailing or leading whitespace.

    if len(pair) > 1:
      # Not a blank line
      like.append(pair[1].strip())
      dislike.append(pair[2].strip())

5. Creating the final text

Once we are done processing the row we can join the strings with a single space, and can finally add these to our likes and dislikes array.

  if len(like) > 0:
    likes.append(" ".join(like))
  if len(dislike) > 0:
    dislikes.append(" ".join(dislike))

6. Using our new data structure

Now we can use these two new lists to process in anyway we choose, either printing each list separately...

from pprint import pprint
print "Likes:"
pprint(likes,indent=4)
print "Dislikes:"
pprint(dislikes,indent=4)

... or zip() them together to create a list of paired likes and dislikes!

print "A set of paired likes and dislikes"
pprint(zip(likes,dislikes),indent=4)

The complete code:

likes_and_dislikes="""

+------------------------------------+-----------------------------------+
| likes                              | dislikes                          |
+------------------------------------+-----------------------------------+
| Meritocracy                        | Favoritism, ass-kissing, politics |
+------------------------------------+-----------------------------------+
| Healthy debates and collaboration  | Ego-driven rhetoric, drama and FUD|
|                                    | to get one's way                  |
+------------------------------------+-----------------------------------+
| Autonomy given by confident leaders| Micro-management by insecure      |
| capable of attracting top-tier     | managers compensating for a weak, |
| talent                             | immature team                     |
+------------------------------------+-----------------------------------+ """

import re
likes,dislikes = [],[]
pairs = re.split("\+-*\+-*\+\n?",likes_and_dislikes)[2:-1] #Drop the header and the tail
for p in pairs:
  like,dislike = [],[]
  for l in p.split('\n'):
    pair = l.split('|')
    if len(pair) > 1:
      # Not a blank line
      like.append(pair[1].strip())
      dislike.append(pair[2].strip())
  if len(like) > 0:
    likes.append(" ".join(like))
  if len(dislike) > 0:
    dislikes.append(" ".join(dislike))
from pprint import pprint
print "Likes:"
pprint(likes,indent=4)
print "Dislikes:"
pprint(dislikes,indent=4)
print "A set of paired likes and dislikes"
pprint(zip(likes,dislikes),indent=4)

This results in:

Likes:
[   'Meritocracy',
    'Healthy debates and collaboration ',
    'Autonomy given by confident leaders capable of attracting top-tier talent']
Dislikes:
[   'Favoritism, ass-kissing, politics',
    "Ego-driven rhetoric, drama and FUD to get one's way",
    'Micro-management by insecure managers compensating for a weak, immature team']
A set of paired likes and dislikes
[   ('Meritocracy', 'Favoritism, ass-kissing, politics'),
    (   'Healthy debates and collaboration ',
        "Ego-driven rhetoric, drama and FUD to get one's way"),
    (   'Autonomy given by confident leaders capable of attracting top-tier talent',
        'Micro-management by insecure managers compensating for a weak, immature team')]

You can see the complete code in action on codepad.