def partitions(sequence, partition_size=None, n_partitions=None,
allow_remainder=True, fill_value=NO_FILL_VALUE):
'''
Partition `sequence` into equal partitions of size `partition_size`, or
determine size automatically given the number of partitions as
`n_partitions`.
If the sequence can't be divided into precisely equal partitions, the last
partition will contain less members than all the other partitions.
Example:
>>> partitions([0, 1, 2, 3, 4], 2)
[[0, 1], [2, 3], [4]]
(You need to give *either* a `partition_size` *or* an `n_partitions`
argument, not both.)
Specify `allow_remainder=False` to enforce that the all the partition sizes
be equal; if there's a remainder while `allow_remainder=False`, an
exception will be raised.
If you want the remainder partition to be of equal size with the other
partitions, you can specify `fill_value` as the padding for the last
partition. A specified value for `fill_value` implies
`allow_remainder=True` and will cause an exception to be raised if
specified with `allow_remainder=False`.
Example:
>>> partitions([0, 1, 2, 3, 4], 3, fill_value=None)
[[0, 1, 2], [3, 4, None]]
'''
sequence_length = len(sequence)
### Validating input: #####################################################
# #
if (partition_size is None) == (n_partitions is None):
raise Exception('You must specify *either* `partition_size` *or* '
'`n_paritions`.')
if fill_value != NO_FILL_VALUE and not allow_remainder:
raise ValueError('`fill_value` cannot be specified if '
'`allow_remainder` is `False`.')
remainder_length = sequence_length % (partition_size if partition_size
is not None else n_partitions)
if not allow_remainder and remainder_length > 0:
raise Exception("You set `allow_remainder=False`, but there's a "
"reminder of %s left." % remainder_length)
# #
### Finished validating input. ############################################
if partition_size is None:
partition_size = math_tools.ceil_div(sequence_length, n_partitions)
if n_partitions is None:
n_partitions = math_tools.ceil_div(sequence_length, partition_size)
enlarged_length = partition_size * n_partitions
blocks = [sequence[i : i + partition_size] for i in
range(0, enlarged_length, partition_size)]
if fill_value != NO_FILL_VALUE and blocks:
filler = itertools.repeat(fill_value,
enlarged_length - sequence_length)
blocks[-1].extend(filler)
return blocks
def partitions(sequence, partition_size=None, *, n_partitions=None,
allow_remainder=True, larger_on_remainder=False,
fill_value=NO_FILL_VALUE):
'''
Partition `sequence` into equal partitions of size `partition_size`, or
determine size automatically given the number of partitions as
`n_partitions`.
If the sequence can't be divided into precisely equal partitions, the last
partition will contain less members than all the other partitions.
Example:
>>> partitions([0, 1, 2, 3, 4], 2)
[[0, 1], [2, 3], [4]]
(You need to give *either* a `partition_size` *or* an `n_partitions`
argument, not both.)
Specify `allow_remainder=False` to enforce that the all the partition sizes
be equal; if there's a remainder while `allow_remainder=False`, an
exception will be raised.
By default, if there's a remainder, the last partition will be smaller than
the others. (e.g. a sequence of 7 items, when partitioned into pairs, will
have 3 pairs and then a partition with only 1 element.) Specify
`larger_on_remainder=True` to make the last partition be a bigger partition
in case there's a remainder. (e.g. a sequence of a 7 items divided into
pairs would result in 2 pairs and one triplet.)
If you want the remainder partition to be of equal size with the other
partitions, you can specify `fill_value` as the padding for the last
partition. A specified value for `fill_value` implies
`allow_remainder=True` and will cause an exception to be raised if
specified with `allow_remainder=False`.
Example:
>>> partitions([0, 1, 2, 3, 4], 3, fill_value='meow')
[[0, 1, 2], [3, 4, 'meow']]
'''
sequence = ensure_iterable_is_sequence(sequence)
sequence_length = len(sequence)
### Validating input: #####################################################
# #
if (partition_size is None) + (n_partitions is None) != 1:
raise Exception('You must specify *either* `partition_size` *or* '
'`n_paritions`.')
remainder_length = sequence_length % (partition_size if partition_size
is not None else n_partitions)
if not allow_remainder and remainder_length > 0:
raise Exception("You set `allow_remainder=False`, but there's a "
"remainder of %s left." % remainder_length)
# #
### Finished validating input. ############################################
if partition_size is None:
floored_partition_size, modulo = divmod(sequence_length,
n_partitions)
if modulo:
if larger_on_remainder:
partition_size = floored_partition_size
n_partitions += 1
# Extra partition will be joined into previous partition
else:
partition_size = floored_partition_size + 1
else: # modulo == 0
partition_size = floored_partition_size
if n_partitions is None:
n_partitions = math_tools.ceil_div(sequence_length, partition_size)
naive_length = partition_size * n_partitions
blocks = [sequence[i : i + partition_size] for i in
range(0, naive_length, partition_size)]
if naive_length != sequence_length:
assert blocks
if larger_on_remainder:
if len(blocks) >= 2:
small_block_to_append_back = blocks[-1]
del blocks[-1]
blocks[-1] += small_block_to_append_back
elif fill_value != NO_FILL_VALUE: # (We use elif because fill is never
# done if `larger_on_remainder=True`.)
filler = itertools.repeat(fill_value,
naive_length - sequence_length)
blocks[-1].extend(filler)
return blocks
def partitions(sequence,
partition_size=None,
n_partitions=None,
allow_remainder=True,
fill_value=NO_FILL_VALUE):
'''
Partition `sequence` into equal partitions of size `partition_size`, or
determine size automatically given the number of partitions as
`n_partitions`.
If the sequence can't be divided into precisely equal partitions, the last
partition will contain less members than all the other partitions.
Example:
>>> partitions([0, 1, 2, 3, 4], 2)
[[0, 1], [2, 3], [4]]
(You need to give *either* a `partition_size` *or* an `n_partitions`
argument, not both.)
Specify `allow_remainder=False` to enforce that the all the partition sizes
be equal; if there's a remainder while `allow_remainder=False`, an
exception will be raised.
If you want the remainder partition to be of equal size with the other
partitions, you can specify `fill_value` as the padding for the last
partition. A specified value for `fill_value` implies
`allow_remainder=True` and will cause an exception to be raised if
specified with `allow_remainder=False`.
Example:
>>> partitions([0, 1, 2, 3, 4], 3, fill_value=None)
[[0, 1, 2], [3, 4, None]]
'''
sequence_length = len(sequence)
### Validating input: #####################################################
# #
if (partition_size is None) == (n_partitions is None):
raise Exception('You must specify *either* `partition_size` *or* '
'`n_paritions`.')
if fill_value != NO_FILL_VALUE and not allow_remainder:
raise ValueError('`fill_value` cannot be specified if '
'`allow_remainder` is `False`.')
remainder_length = sequence_length % (partition_size if partition_size
is not None else n_partitions)
if not allow_remainder and remainder_length > 0:
raise Exception("You set `allow_remainder=False`, but there's a "
"reminder of %s left." % remainder_length)
# #
### Finished validating input. ############################################
if partition_size is None:
partition_size = math_tools.ceil_div(sequence_length, n_partitions)
if n_partitions is None:
n_partitions = math_tools.ceil_div(sequence_length, partition_size)
enlarged_length = partition_size * n_partitions
blocks = [
sequence[i:i + partition_size]
for i in range(0, enlarged_length, partition_size)
]
if fill_value != NO_FILL_VALUE and blocks:
filler = itertools.repeat(fill_value,
enlarged_length - sequence_length)
blocks[-1].extend(filler)
return blocks
def partitions(
sequence,
partition_size=None,
*,
n_partitions=None,
allow_remainder=True,
larger_on_remainder=False,
fill_value=NO_FILL_VALUE
):
"""
Partition `sequence` into equal partitions of size `partition_size`, or
determine size automatically given the number of partitions as
`n_partitions`.
If the sequence can't be divided into precisely equal partitions, the last
partition will contain less members than all the other partitions.
Example:
>>> partitions([0, 1, 2, 3, 4], 2)
[[0, 1], [2, 3], [4]]
(You need to give *either* a `partition_size` *or* an `n_partitions`
argument, not both.)
Specify `allow_remainder=False` to enforce that the all the partition sizes
be equal; if there's a remainder while `allow_remainder=False`, an
exception will be raised.
By default, if there's a remainder, the last partition will be smaller than
the others. (e.g. a sequence of 7 items, when partitioned into pairs, will
have 3 pairs and then a partition with only 1 element.) Specify
`larger_on_remainder=True` to make the last partition be a bigger partition
in case there's a remainder. (e.g. a sequence of a 7 items divided into
pairs would result in 2 pairs and one triplet.)
If you want the remainder partition to be of equal size with the other
partitions, you can specify `fill_value` as the padding for the last
partition. A specified value for `fill_value` implies
`allow_remainder=True` and will cause an exception to be raised if
specified with `allow_remainder=False`.
Example:
>>> partitions([0, 1, 2, 3, 4], 3, fill_value='meow')
[[0, 1, 2], [3, 4, 'meow']]
"""
sequence = ensure_iterable_is_sequence(sequence)
sequence_length = len(sequence)
### Validating input: #####################################################
# #
if (partition_size is None) + (n_partitions is None) != 1:
raise Exception("You must specify *either* `partition_size` *or* " "`n_paritions`.")
remainder_length = sequence_length % (partition_size if partition_size is not None else n_partitions)
if not allow_remainder and remainder_length > 0:
raise Exception("You set `allow_remainder=False`, but there's a " "remainder of %s left." % remainder_length)
# #
### Finished validating input. ############################################
if partition_size is None:
floored_partition_size, modulo = divmod(sequence_length, n_partitions)
if modulo:
if larger_on_remainder:
partition_size = floored_partition_size
n_partitions += 1
# Extra partition will be joined into previous partition
else:
partition_size = floored_partition_size + 1
else: # modulo == 0
partition_size = floored_partition_size
if n_partitions is None:
n_partitions = math_tools.ceil_div(sequence_length, partition_size)
naive_length = partition_size * n_partitions
blocks = [sequence[i : i + partition_size] for i in range(0, naive_length, partition_size)]
if naive_length != sequence_length:
assert blocks
if larger_on_remainder:
if len(blocks) >= 2:
small_block_to_append_back = blocks[-1]
del blocks[-1]
blocks[-1] += small_block_to_append_back
elif fill_value != NO_FILL_VALUE: # (We use elif because fill is never
# done if `larger_on_remainder=True`.)
filler = itertools.repeat(fill_value, naive_length - sequence_length)
blocks[-1].extend(filler)
return blocks
