def filter(polylines, min_len=<NUM_LIT:20>):
filtered = []<EOL>for n in range(len(polylines) - <NUM_LIT:1>, -<NUM_LIT:1>, -<NUM_LIT:1>):<EOL><INDENT>if lengths(polylines[n]).sum() < min_len:<EOL><INDENT>filtered.append(polylines.pop(n))<EOL><DEDENT><DEDENT>return filtered<EOL>
filter polylines shorter than given min length