On second thought, we would NOT like to parse escape characters as maya
would complain later:

   for nodeName, currIndent in ((line.strip(),
                                  len(line) - len(line.lstrip()))
                                 for line in hierarchy.split("\n")
                                 if line.strip()):




On Fri, Sep 16, 2016 at 4:04 PM, Alok Gandhi <alok.gandhi2...@gmail.com>
wrote:

> IMHO, parsing the string is just a matter of administrative logic and
> should not be bothered with when focussing on the business logic (which, in
> this case, is recreating the hierarchy).
>
> Sure JSON, YAML, and XML(ugly) are a few options to choose from for
> parsing the string. In the end, It is just a detail to get the data,
> nothing more, nothing less.
>
> What is important is how we deal with that data in the most efficient,
> optimized and readable way.
>
> So here is my implementation, parsing your original indented string. This
> definitely covers your points 1 and 2.  3 is a matter of opinion and is
> subjective.
>
> Few things to note:
>
>    - Right in the beginning, we parse the string in a single line,
>    keeping the administrative logic out from the rest of our business code.
>    You can easily replace this single line with whatever parser you want.
>
>
>    - I am using `namedtuple` for readability they are lightweight and
>    require no more memory than regular tuples.
>
>
>    - `bisect` uses a basic bisection algorithm, an improvement over the
>    common approach for finding an insertion point in a sorted list without
>    having to sort it again.
>
>
>    - This completely eliminates multiple calls to parent() as in your
>    original implementation. For each line in the input string, we parent only
>    once, no need to go back up or down in the hierarchy with multiple
>    if-elif-else. This is more efficient and straight forward.
>
>
>    - Handles multiple hierarchies starting from the root (which your
>    version also covered I think)
>
>
>    - Space characters are not a problem on an empty line(In my example, I
>    have deliberate space chars to demonstrate that). On that note, please note
>    that I am using line.strip(' ') instead of line.strip(), the reason being
>    you can still parse escape characters like \r \t \n etc., strip() eats them
>    up as they are whitespaces as well.
>
>
> ----------------------------------------------------------
>
> from collections import namedtuplefrom bisect import bisect_left
> import pymel.core as pm
>
> def hierarchy_from_string(hierarchy):
>     NodeInfo = namedtuple('NodeInfo', 'node indent')
>     nodeInfos = []
>     for nodeName, currIndent in ((line.strip(' '),
>                                   len(line) - len(line.lstrip(' ')))
>                                  for line in hierarchy.split("\n")
>                                  if line.strip()):
>
>         node = (pm.ls(nodeName)[0] if pm.ls(nodeName)
>                 else pm.createNode('transform', name=nodeName))
>
>         parentIndex = bisect_left([nodeInfo.indent for nodeInfo in nodeInfos],
>                                   currIndent)
>
>         parentNode = (nodeInfos[parentIndex - 1].node
>                       if parentIndex - 1 >= 0 else None)
>
>         nodeInfo = NodeInfo(node=node, indent=currIndent)
>
>         if parentIndex < len(nodeInfos):
>             nodeInfos[parentIndex] = nodeInfo
>         else:
>             nodeInfos.append(nodeInfo)
>
>         pm.parent(node, parentNode)
>
>
> hierarchy_from_string("""\rig    implementation        geometry        
> skeleton    interface        controls        previewfoo    bar            baz 
>                     alice            bob""")
>
>
> - Alok
>



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