address review comments

scipy/sparse/_base.py

@@ -338,11 +338,10 @@ def __str__(self):
 
  A = self.tocoo()
 
-
  # helper function, outputs "(i,j) v"
  def tostr(coords, data):
- triples = zip(list(zip(*coords)), data)
- return '\n'.join([(' {}\t{}'.format(*t)) for t in triples])
+ pairs = zip(zip(*coords), data)
+ return '\n'.join(f' {idx}\t{val}' for idx, val in pairs)
 
  out = repr(self)
  if self.nnz == 0:
@@ -353,7 +352,7 @@ def tostr(coords, data):
  half = maxprint // 2
  out += tostr(tuple(c[:half] for c in A.coords), A.data[:half])
  out += "\n :\t:\n"
- half = maxprint - maxprint//2
+ half = maxprint - half
  out += tostr(tuple(c[-half:] for c in A.coords), A.data[-half:])
  else:
  out += tostr(A.coords, A.data)

scipy/sparse/_lil.py

@@ -111,17 +111,6 @@ def count_nonzero(self):
  _getnnz.__doc__ = _spbase._getnnz.__doc__
  count_nonzero.__doc__ = _spbase.count_nonzero.__doc__
 
- def __str__(self):
- val = repr(self)
- if self.nnz == 0:
- return val
-
- val += '\n Coords\tValue\n'
- for i, row in enumerate(self.rows):
- for pos, j in enumerate(row):
- val += f" {str((i, j))}\t{str(self.data[i][pos])}\n"
- return val[:-1]
-
  def getrowview(self, i):
  """Returns a view of the 'i'th row (without copying).
  """