TreeMap¶

Contents

Constructor Summary
Methods Summary
Constructor and Methods Details

Constructor Summary ¶

Constructor	Description
`TreeMap(comparator=None)`	Constructs a new, empty TreeMap. You can supply a comparator if your keys do not implement rich comparison methods (you do not need this for most Python built-in objects).

Methods Summary ¶

Method	Description
`size()`	Returns the number of entries in the tree.
`contains_key(key)`	Returns `True` if this map contains a mapping for the specified key. Returns `False` otherwise.
`contains_value(value)`	Returns `True` if at least 1 key is mapped to the specified value. Returns `False` otherwise.
`get(key)`	Returns the value to which the specified key is mapped to. Returns `None` is no such mapping exists.
`comparator()`	Returns the comparator if you supplied one. Returns `None` otherwise.
`first_key()`	Returns the first/smallest/left-most key. `KeyError` is raised if no such key exists
`last_key()`	Returns the last/largest/right-most key. `KeyError` is raised if no such key exists
`put(key, value)`	Associates the key with the value. If the key already exists, the old associated value is replaced with the new value.
`remove(key)`	If the key exists, remove the entry and return the associated value. Returns `None` otherwise.
`clear()`	Removes all entries and reset all the fields.
`first_entry()`	Returns the first/smallest/left-most entry. Returns `None` if no such entry exists.
`last_entry()`	Returns the last/largest/right-most entry. Returns `None` if no such entry exists.
`poll_first_entry()`	Removes and returns the first entry. Returns `None` if no such entry exists.
`poll_last_entry()`	Removes and returns the last entry. Returns `None` if no such entry exists.
`lower_entry(key)`	Returns the entry with the greatest key less than the specified key. Returns `None` if no such entry exists.
`lower_key(key)`	Returns the greatest key less than the specified key. Returns `None` if no such key exists.
`floor_entry(key)`	Returns the entry with the greatest key less than or equal to the specified key. Returns `None` if no such entry exists.
`floor_key(key)`	Returns the greatest key less than or equal to the specified key. Returns `None` if no such key exists.
`ceiling_entry(key)`	Returns the entry with the smallest key greater than or equal to the specified key. Returns `None` if no such entry exists.
`ceiling_key(key)`	Returns the smallest key greater than or equal to the specified key. Returns `None` if no such key exists.
`higher_entry(key)`	Returns the entry with the smallest key greater than the specified key. Returns `None` if no such entry exists.
`higher_key(key)`	Returns the smallest key greater than the specified key. Returns `None` if no such key exists.
`key_set()`	Returns a set view of all the keys in the map. The object returned is iterable and the iteration goes from the smallest to the largest key.
`navigable_key_set()`	Same as `key_set()`.
`descending_key_set()`	Similar to `key_set()` but the iteration goes from the largest to the smallest key.
`values()`	Returns a collection view of the values in the map. The object returned is iterable.
`entry_set()`	Returns a set view of the entries in the map. The object returned is iterable and the iteration from the entry with the smallest to the entry with the largest key.
`descending_map()`	Returns a reverse order view of the map.
`sub_map(from_key, to_key,` `from_inclusive=True, to_inclusive=False)`	Returns a view of the portion of this map whose keys range from from_key to to_key. The default includes from_key but excludes to_key.
`head_map(to_key, inclusive=False)`	Returns a view of the portion of this map whose keys are less than (or equal to, if inclusive is true) to_key.
`tail_map(from_key, inclusive=True)`	Returns a view of the portion of this map whose keys are greater than (or equal to, if inclusive is true) from_key.

Methods is_empty(), put_all(), equals(), hash_code(), to_string(), get_or_default(), for_each(), replace_all(), put_if_absent(), replace(), compute_if_absent(), compute_if_present(), compute() and classes SimpleEntry, SimpleImmutableEntry, Entry are also implemented. For advanced users, please consult the source code.

Constructor and Methods Details ¶

class TreeMap(comparator=None)¶

Constructs a new, empty TreeMap. You can supply a comparator if your keys do not implement rich comparison methods (you do not need this for most Python built-in objects). The comparator function should take 2 arguments a and b, return a negative int if a < b, return a positive int if a > b, and return 0 if a == b. E.g.

def cmp(a, b):
    if a < b:
        return -1
    elif a > b:
        return 1
    else:
        return 0

size()¶: Returns the number of entries in the tree.

Tip

You can also use the built-in len() function to get the size of the tree.

contains_key(key)¶

Returns True if this map contains a mapping for the specified key. Returns False otherwise.

Raises: TypeError – If key is not comparable to the keys currently in the map.

Tip

You can also use the key in self syntax to check whether the map contains the ky.

contains_value(value)¶: Returns``True`` if at least 1 key is mapped to the specified value. Returns False otherwise.

get(key)¶

Returns the value to which the specified key is mapped to. Returns None is no such mapping exists.

Raises: TypeError – If key is not comparable to the keys currently in the map.

Tip

You can also get the value using the self[key] syntax. Unlike get(), a KeyError is raised if the key is not found.

comparator()¶: Returns the comparator if you supplied one. Returns None otherwise.

first_key()¶

Returns the first/smallest/left-most key.

Raises: KeyError – if the map is empty

last_key()¶

Returns the last/largest/right-most key.

Raises: KeyError – if the map is empty

put(key, value)¶

Associates the key with the value. If the key already exists, the old associated value is replaced with the new value.

Raises: TypeError – If key is not comparable to the keys currently in the map.

Tip

You can also insert a key-value pair using the self[key] = value syntax.

remove(key)¶

If the key exists, remove the entry and return the associated value. Returns None otherwise.

Raises: TypeError – If key is not comparable to the keys currently in the map.

Tip

You can also remove an entry using the del self[key] syntax. Unlike put(), a KeyError is raised if the key is not found.

clear()¶: Removes all entries and reset all the fields.

first_entry()¶

Returns the first/smallest/left-most entry. Returns None if no such entry exists.

Return type: Entry

last_entry()¶

Returns the last/largest/right-most entry. Returns None if no such entry exists.

Return type: Entry

poll_first_entry()¶

Removes and returns the first entry. Returns None if no such entry exists.

Return type: Entry

poll_last_entry()¶

Removes and returns the last entry. Returns None if no such entry exists.

Return type: Entry

lower_entry(key)¶

Returns the entry with the greatest key less than the specified key. Returns None if no such entry exists.

Return type: Entry
Raises: TypeError – If key is not comparable to the keys currently in the map.

lower_key(key)¶

Returns the greatest key less than the specified key. Returns None if no such key exists.

Raises: TypeError – If key is not comparable to the keys currently in the map.

floor_entry(key)¶

Returns the entry with the greatest key less than or equal to the specified key. Returns None if no such entry exists.

Return type: Entry
Raises: TypeError – If key is not comparable to the keys currently in the map.

floor_key(key)¶

Returns the greatest key less than or equal to the specified key. Returns None if no such key exists.

Raises: TypeError – If key is not comparable to the keys currently in the map.

ceiling_entry(key)¶

Returns the entry with the smallest key greater than or equal to the specified key. Returns None if no such entry exists.

Return type: Entry
Raises: TypeError – If key is not comparable to the keys currently in the map.

ceiling_key(key)¶

Returns the smallest key greater than or equal to the specified key. Returns None if no such key exists.

Raises: TypeError – If key is not comparable to the keys currently in the map.

higher_entry(key)¶

Returns the entry with the smallest key greater than the specified key. Returns None if no such entry exists.

Return type: Entry
Raises: TypeError – If key is not comparable to the keys currently in the map.

higher_key(key)¶

Returns the smallest key greater than the specified key. Returns None if no such key exists.

Raises: TypeError – If key is not comparable to the keys currently in the map.

key_set()¶

Returns a set view of all the keys in the map. The object returned is iterable and the iteration goes from the smallest to the largest key.

Return type: NavigableSet

navigable_key_set()¶

Same as key_set().

Return type: NavigableSet

descending_key_set()¶

Similar to key_set() but the iteration goes from the largest to the smallest key.

Return type: NavigableSet

values()¶

Returns a collection view of the values in the map. The object returned is iterable.

Return type: Values

entry_set()¶

Returns a set view of the entries in the map. The object returned is iterable and the iteration from the entry with the smallest to the entry with the largest key.

Return type: EntrySet

descending_map()¶

Returns a reverse order view of the map.

Return type: NavigableMap

sub_map(from_key, to_key, from_inclusive=True, to_inclusive=False)¶

Returns a view of the portion of this map whose keys range from from_key to to_key. The default includes from_key but excludes to_key.

Return type

NavigableMap

Raises

TypeError – If from_key or to_key is not comparable to the keys currently in the map.
KeyError – If from_key is greater than to_key; or if this map itself has a restricted range, and from_key or to_key lies outside the bounds of the range.

head_map(to_key, inclusive=False)¶

Returns a view of the portion of this map whose keys are less than (or equal to, if inclusive is true) to_key.

Raises

TypeError – If to_key is not comparable to the keys currently in the map.
KeyError – If this map itself has a restricted range, and to_key lies outside the bounds of the range.

tail_map(from_key, inclusive=True)¶

Returns a view of the portion of this map whose keys are greater than (or equal to, if inclusive is true) from_key.

Raises

TypeError – If from_key is not comparable to the keys currently in the map.
KeyError – If this map itself has a restricted range, and from_key lies outside the bounds of the range.

TreeMap¶

Constructor Summary¶

Methods Summary¶

Constructor and Methods Details¶

Constructor Summary ¶

Methods Summary ¶

Constructor and Methods Details ¶