Utils

tangible.utils.connect_2d_shapes(shapes, layer_distance, orientation)[source]

Convert a list of 2D shapes to a 3D shape.

Take a list of 2D shapes and create a 3D shape from it. Each layer is separated by the specified layer distance.

Parameters:
  • shapes (Each shape in the list should be an AST object.) – List of shapes.
  • layer_distance (int or float) – The distance between two layers.
  • orientation (str or unicode) – Either ‘horizontal’ or ‘vertical’
Returns:

ast.Union
tangible.utils.pairwise(iterable)[source]

Iterate over an iterable in pairs.

This is an implementation of a moving window over an iterable with 2 items. Each group in the resulting list contains 2 items. This means that the original iterable needs to contain at least 2 items, otherwise this function will return an empty list.

Example:

[1, 2, 3, 4] -> [(1, 2), (2, 3), (3, 4)]
Parameters:iterable (Any iterable type (e.g. a list or a tuple).) – An iterable containing at least 2 items.
Returns:A generator returning pairwise items.
Return type:itertools.izip
tangible.utils.reduceby(iterable, keyfunc, reducefunc, init)[source]

Combination of itertools.groupby() and reduce().

This generator iterates over the iterable. The values are reduced using reducefunc and init as long as keyfunc(item) returns the same value.

A possible use case would be to aggregate website visits and to group them by month. The corresponding SQL statement would be:

SELECT SUM(visit_count) FROM visits GROUP BY month;

Example:

>>> keyfunc = lambda x: x % 2 == 0
>>> reducefunc = lambda x, y: x + y
>>> values = [1, 3, 5, 6, 8, 11]
>>> groups = utils.reduceby(values, keyfunc, reducefunc, 0)
>>> groups
<generator object reduceby at 0xedc5a0>
>>> list(groups)
[9, 14, 11]
Parameters:
  • iterable – An iterable to reduce. The iterable should be presorted.
  • keyfunc – A key function. It should return the same value for all items belonging to the same group.
  • reducefunc – The reduce function.
  • init – The initial value for the reduction.
Returns:

A generator returning the reduced groups.
Return type:

generator