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"""

=============

Row tests

=============

>>> row = Row([1, 2, 3, 4])

>>> row[1]

2

>>> row[1:3]

Row([2, 3])

=============

Table tests

=============

Create an empty table

>>> t3x4 = Table.blank(3, 4)

>>> t3x4

Table(Row([None, None, None, None]),

Row([None, None, None, None]),

Row([None, None, None, None]))

>>> for i in range(3):

... for j in range(4):

... t3x4[i][j] = chr(65 + i * 4 + j)

...

>>> t3x4

Table(Row(['A', 'B', 'C', 'D']),

Row(['E', 'F', 'G', 'H']),

Row(['I', 'J', 'K', 'L']))

>>> t3x4[1]

Row(['E', 'F', 'G', 'H'])

>>> t3x4[1:]

Table(Row(['E', 'F', 'G', 'H']),

Row(['I', 'J', 'K', 'L']))

>>> t3x4[1][2]

'G'

>>> t3x4[1, 2]

'G'

Slicing returns a table, so index 2 below would be trying to get row index 2

of a table that has only rows 0 and 1:

>>> t3x4[1:][2]

Traceback (most recent call last):

...

IndexError: no row at index 2 of 2-row table

>>> t3x4[:, 2]

Table(Row(['C']),

Row(['G']),

Row(['K']))

>>> t3x4[1:, 2]

Table(Row(['G']),

Row(['K']))

>>> t3x4[1, 2:]

Row(['G', 'H'])

>>> t3x4[:, 1:3]

Table(Row(['B', 'C']),

Row(['F', 'G']),

Row(['J', 'K']))

>>> t3x4[:, :]

Table(Row(['A', 'B', 'C', 'D']),

Row(['E', 'F', 'G', 'H']),

Row(['I', 'J', 'K', 'L']))

>>> t3x4[:, :] == t3x4

True

===============

Error handling

===============

>>> t3x4[5]

Traceback (most recent call last):

...

IndexError: no row at index 5 of 3-row table

>>> t3x4[1,]

Traceback (most recent call last):

...

IndexError: index must be [i] or [i, j]

>>> t3x4[1, 2, 3]

Traceback (most recent call last):

...

IndexError: index must be [i] or [i, j]

>>> t3x4[10:, 2]

Traceback (most recent call last):

...

ValueError: Table must have at least one row.

>>> t3x4[1, 20:]

Traceback (most recent call last):

...

ValueError: Row must have at least one cell.

"""

import collections

class Row(collections.UserList):

def __init__(self, cells):

super().__init__(cells)

if len(self) < 1:

raise ValueError('Row must have at least one cell.')

def __getitem__(self, position):

if isinstance(position, slice):

return Row(self.data[position]) # build sub-row

else:

return self.data[position] # return cell value

def __repr__(self):

return '%s(%r)' % (self.__class__.__name__, self.data)

class Table(collections.UserList):

"""A table with rows, all of the same width"""

def __init__(self, rows):

super().__init__(Row(r) for r in rows)

if len(self) < 1:

raise ValueError('Table must have at least one row.')

self.width = self.check_width()

def check_width(self):

row_widths = {len(row) for row in self.data}

if len(row_widths) > 1:

raise ValueError('All rows must have equal length.')

return row_widths.pop()

@classmethod

def blank(class_, rows, columns, filler=None):

return class_([[filler] * columns for i in range(rows)])

def __repr__(self):

prefix = '%s(' % self.__class__.__name__

indent = ' ' * len(prefix)

rows = (',\n' + indent).join(

repr(row) for row in self.data)

return prefix + rows + ')'

def _get_indexes(self, position):

if isinstance(position, tuple): # multiple indexes

if len(position) == 2: # two indexes: t[i, j]

return position

else:

raise IndexError('index must be [i] or [i, j]')

else: # one index: t[i]

return position, None

def __getitem__(self, position):

i, j = self._get_indexes(position)

if isinstance(i, slice):

if j is None: # build sub-table w/ full rows

return Table(self.data[position])

else: # build sub-table w/ sub-rows

return Table(cells[j] for cells in self.data[i])

else: # i is number

try:

row = self.data[i]

except IndexError:

msg = 'no row at index %r of %d-row table'

raise IndexError(msg % (position, len(self)))

if j is None: # return row at table[i]

return row

else:

return row[j] # return row[j] or row[a:b]