sequences#

Source code: sensai/util/sequences.py

concat_sequences(seqs: Sequence[Sequence[T]]) → List[T][source]#
get_first_duplicate(seq: Sequence[T]) → Optional[T][source]#

Returns the first duplicate in a sequence or None

Parameters:

seq – a sequence of hashable elements

Returns:

floor_index(arr, value) → Optional[int][source]#

Finds the rightmost/largest index in a sorted array where the value is less than or equal to the given value

Parameters:

  • arr – the sorted array of values

  • value – the value to search for

Returns:

the index or None if there is no such index

ceil_index(arr, value) → Optional[int][source]#

finds the leftmost/lowest index in a sorted array where the value is greater than or equal to the given value

Parameters:

  • arr – the sorted array of values

  • value – the value to search for

Returns:

the index or None if there is no such index

closest_index(arr, value) → Optional[int][source]#

Finds the index in the given array where the value is closest to the given value. If two subsequent values have the same distance, the smaller index is returned.

Parameters:

  • arr – the array to search in

  • value – the value to search for

Returns:

the index or None if the array is empty

ceil_value(keys, key_value, values=None) → Optional[Any][source]#

For a sorted array of keys (and a an array of corresponding values), returns the corresponding value (values[i]) for the lowest index i where keys[i] >= keyValue

Parameters:

  • keys – the sorted array of keys for in which to search for the value closest to keyValue

  • key_value – the key to search for

  • values – the array from which to retrieve the value; if None, use keys

Returns:

the value or None if no such value exists

floor_value(keys, key_value, values=None, fallback_first=False) → Optional[Any][source]#

For a sorted array of keys (and an array of corresponding values), returns the corresponding value (values[i]) for the largest index i in keys where keys[i] <= keyValue.

Parameters:

  • keys – the sorted array of keys in which to perform the lookup

  • key_value – the key for which to perform the lookup

  • values – the sorted array of values; if None, use keys as values

  • fallback_first – if True, then return the first value instead of None for the case where no floor value exists

Returns:

the floor value

closest_value(keys, key_value, values=None) → Optional[Any][source]#

For a sorted array of keys (and an array of corresponding values), finds the value at the index where the key is closest to the given key value. If two subsequent values are equally close, the value at the smaller index is returned.

value_slice_inner(keys, lower_bound_key, upper_bound_key, values=None)[source]#

For a sorted array of keys (and an array of corresponding values), finds indices i, j such that i is the lowest key where keys[i] >= lowerBoundKey and j is the largest key where keys[j] <= upperBoundKey, and returns the corresponding slice of values values[i:j+1], i.e. the slice will not include the bounds keys if they are not present in the keys array.

Parameters:

  • keys – the sorted array of key values

  • lower_bound_key – the key value defining the lower bound

  • upper_bound_key – the key value defining the upper bound

  • values – the sorted array of values; if None, use keys

Returns:

the corresponding slice of values

value_slice_outer(keys, lower_bound_key, upper_bound_key, values=None, fallback_bounds=False)[source]#

For a sorted array of keys and an array of corresponding values, finds indices i, j such that i is the largest key where keys[i] <= lowerBoundKey and j is the lowest key where keys[j] <= upperBoundKey, and returns the corresponding slice of values values[i:j+1]. If such indices do not exists and fallbackBounds==True, the array bounds are used (i.e. 0 or len-1). If such indices do not exists and fallbackBounds==False, an exception is raised. This returned slice is an outer slice, which is the smallest slice that definitely contains two given bounds (for fallbackBounds==False).

Parameters:

  • keys – the sorted array of key values

  • lower_bound_key – the key value defining the lower bound

  • upper_bound_key – the key value defining the upper bound

  • values – the sorted array of values; if None, use keys

  • fallback_bounds – whether to use the smallest/largest index (i.e. 0 or len-1) as a fallback in case no matching bounds exist

Returns:

the corresponding slice of values