hand in my homework (in page 463) :D

10-seq-hacking/vector_v5.py

@@ -269,15 +269,24 @@ def angles(self): # <3>
  return (self.angle(n) for n in range(1, len(self)))
 
  def __format__(self, fmt_spec=''):
+ ellipsis = ''
+ limit_num = len(self)
+ if fmt_spec.endswith('*'):
+ fmt_spec = fmt_spec[:-1]
+ elif len(self) > 30:
+ limit_num = 30
+ ellipsis = ', ...'
+
  if fmt_spec.endswith('h'): # hyperspherical coordinates
  fmt_spec = fmt_spec[:-1]
  coords = itertools.chain([abs(self)],
  self.angles()) # <4>
- outer_fmt = '<{}>' # <5>
+ outer_fmt = '<{{}}{}>'.format(ellipsis) # <5>
  else:
  coords = self
- outer_fmt = '({})' # <6>
- components = (format(c, fmt_spec) for c in coords) # <7>
+ outer_fmt = '({{}}{})'.format(ellipsis) # <6>
+ components = (format(c, fmt_spec)
+ for c in itertools.islice(coords, limit_num)) # <7>
  return outer_fmt.format(', '.join(components)) # <8>
 
  @classmethod