This function accepts a sequence and a template of how the sequence should be reshaped.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 | ```
def reshape(seq, how):
"""Reshape the sequence according to the template in ``how``.
Examples
========
>>> from sympy.utilities import reshape
>>> seq = range(1, 9)
>>> reshape(seq, [4]) # lists of 4
[[1, 2, 3, 4], [5, 6, 7, 8]]
>>> reshape(seq, (4,)) # tuples of 4
[(1, 2, 3, 4), (5, 6, 7, 8)]
>>> reshape(seq, (2, 2)) # tuples of 4
[(1, 2, 3, 4), (5, 6, 7, 8)]
>>> reshape(seq, (2, [2])) # (i, i, [i, i])
[(1, 2, [3, 4]), (5, 6, [7, 8])]
>>> reshape(seq, ((2,), [2])) # etc....
[((1, 2), [3, 4]), ((5, 6), [7, 8])]
>>> reshape(seq, (1, [2], 1))
[(1, [2, 3], 4), (5, [6, 7], 8)]
>>> reshape(tuple(seq), ([[1], 1, (2,)],))
(([[1], 2, (3, 4)],), ([[5], 6, (7, 8)],))
>>> reshape(tuple(seq), ([1], 1, (2,)))
(([1], 2, (3, 4)), ([5], 6, (7, 8)))
>>> reshape(range(12), [2, [3, set([2])], (1, (3,), 1)])
[[0, 1, [2, 3, 4, set([5, 6])], (7, (8, 9, 10), 11)]]
"""
m = sum(flatten(how))
n, rem = divmod(len(seq), m)
if m < 0 or rem:
raise ValueError('template must sum to positive number '
'that divides the length of the sequence')
i = 0
how_type = type(how)
rv = [None]*n
for k in range(len(rv)):
rv[k] = []
for hi in how:
if type(hi) is int:
rv[k].extend(seq[i: i + hi])
i += hi
else:
n = sum(flatten(hi))
hi_type = type(hi)
rv[k].append(hi_type(reshape(seq[i: i + n], hi)[0]))
i += n
rv[k] = how_type(rv[k])
return type(seq)(rv)
``` |

This is makes data entry convenient when dealing with nested tuples. e.g. if a routine requires a list of range/ value tuples -- range = (1, 3); value = 4. You can enter the flat data and reshape it into the range/value tuples:

```
reshape([1, 2, 3, 4, 5, 6], [(2,),1]) -> [[(1, 2), 3], [(4, 5), 6]]
```

The returned container will be the same as the type of the first argument and inside will be 1 or more repeated iterable that have the structure of the second argument.

cool

Nice. But, I think you want 'how' for 'g' in line 34 and a bracket around 1,2,3,4,5,6 in the sample you gave. I have a use for the code. Thanks.

Thanks! It looks like you are correct. I'm not sure how to edit this but your comments indicate clearly what needs to change so I won't change anything for now.

OK, I see how to edit this, so I made the changes and added another example involving a set that indicated a problem in the code.

Chris, thank you very much for this contribution !