Convert a Frame String to Frame List


Deadline passes frames to Draft in the form of a Frame Range (such as "1-100"). Converting this to a List of Frame Numbers can be non-trivial, given how complex Frame Strings can get (e.g., "105,200-400x3,500-600step4,1-100" is a valid Frame String).


Fortunately, we have added a function in Draft’s DraftParamParser helper script specifically to alleviate this problem:

import Draft
from DraftParamParser import * #Needed to use the utility function

#Sample input
frameRange = "1-10x2,11-15" #Equivalent to 1,3,5,7,9,11,12,13,14,15

frameList = FrameRangeToFrames( frameRange )

#You can now iterate over the Frame List
for frameNumber in frameList:
    #Do something with the FrameNumber
    print frameNumber


In addition to the obvious functionality of expanding a Frame Range string into a list of Frames, the FrameRangeToFrames() function also sorts the frames in ascending order and ensures that there are no duplicate frames in the List.

Simple Frame Ranges

It should be noted that Deadline also passes the First and Last frames in the given Frame Range as separate arguments to Draft (startFrame and endFrame, respectively). If you’re not interested in supporting complex Frame Ranges in your Template, you can simply use these values to generate a list of frames as follows:

for frameNumber in range( startFrame, endFrame + 1 ):
    #Do something with frameNumber
    print frameNumber