code.kerkeslager.com Git - climbing.kerkeslager.com/blob - src/core/utils.py

   1 def merge(xs:iter, ys:iter, x_key, y_key=None):
   2     if y_key is None:
   3         y_key = x_key
   4
   5     if isinstance(x_key, str):
   6         x_attr = x_key
   7         x_key = lambda x: getattr(x, x_attr)
   8
   9     if isinstance(y_key, str):
  10         y_attr = y_key
  11         y_key = lambda y: getattr(y, y_attr)
  12
  13     xs = iter(xs)
  14     ys = iter(ys)
  15
  16     try:
  17         x = next(xs)
  18     except StopIteration:
  19         x = None
  20
  21     try:
  22         y = next(ys)
  23     except StopIteration:
  24         y = None
  25
  26     while x and y:
  27         if x_key(x) < y_key(y):
  28             yield x
  29             try:
  30                 x = next(xs)
  31             except StopIteration:
  32                 x = None
  33         else:
  34             yield y
  35             try:
  36                 y = next(ys)
  37             except StopIteration:
  38                 y = None
  39
  40     while x:
  41         yield x
  42         try:
  43             x = next(xs)
  44         except StopIteration:
  45             x = None
  46
  47     while y:
  48         yield y
  49         try:
  50             y = next(ys)
  51         except StopIteration:
  52             y = None
  53
  54