Python Ranges

https://python-ranges.readthedocs.io/en/latest/
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Python Ranges provides continuous Range, RangeSet, and RangeDict data structures for Python,...
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### Range Constructor Examples

Source: https://python-ranges.readthedocs.io/en/latest/about.html

Demonstrates various ways to instantiate a Range object, including using start and end arguments, string representations, copying existing ranges, and specifying bound inclusivity.

```python
Range(2, 5) # two arguments, start and end respectively
```

```python
Range(‘[2..5)’) # one argument, of type String - resolves to a numeric range. Use ‘..’ or ‘,’ as separator
```

```python
Range(Range(2, 5)) # one argument, of type Range - copies the given Range
```

```python
Range(start=2, end=5) # keyword arguments specify start and end. If not given, they default to -Inf/Inf
```

```python
Range() # no arguments - infinite bounds by default
```

```python
Range(2, 5, include_start=False, include_end=True)
```

```python
Range(‘(2, 5]’)
```

--------------------------------

### Create Range from Keyword Arguments

Source: https://python-ranges.readthedocs.io/en/latest/about.html

Constructs a Range object using keyword arguments 'start' and/or 'end'. Default values are negative infinity for start and positive infinity for end if not provided. Custom inclusivity can also be specified.

```python
g = Range(start=3, end=5)  # [3, 5)
h = Range(start=3)  # [3, inf)
i = Range(end=5)  # [-inf, 5)
j = Range(start=3, end=5, include_start=False, include_end=True)  # (3, 5]
```

--------------------------------

### Range with String Objects

Source: https://python-ranges.readthedocs.io/en/latest/about.html

Constructs a Range using strings for start and end, demonstrating lexicographical comparisons for checking inclusion.

```python
n = Range("killer", "rabbit")
>>> print("grenade" in n)  # False
>>> print("pin" in n)  # True
>>> print("three" in n)  # False
```

--------------------------------

### Create Range from Positional Arguments

Source: https://python-ranges.readthedocs.io/en/latest/about.html

Constructs a Range object using two positional arguments for start and end. The condition start <= end must be true. Includes examples with custom inclusivity for start and end.

```python
e = Range(3, 5)
>>> print(e)  # [3, 5)
f = Range(3, 5, include_start=False, include_end=True)
>>> print(f)  # (3, 5]
```

--------------------------------

### Create Range from String

Source: https://python-ranges.readthedocs.io/en/latest/about.html

Constructs a Range object from a string in the format '[start, end)'. Both '()' and '[]' are valid brackets. The start and end must be parsable as floats, and start <= end must be true.

```python
c = Range("(-3, 5.5)")  # Infers include_start and include_end to both be false
d = Range("[-3, 5.5)")  # Infers include_start to be true, include_end to be false
```

--------------------------------

### Range with Date Objects

Source: https://python-ranges.readthedocs.io/en/latest/about.html

Constructs a Range using datetime.date objects for start and end, and checks for date inclusion within the range.

```python
import datetime
m = Range(datetime.date(1478, 11, 1), datetime.date(1834, 7, 15))
>>> print(datetime.date(1492, 8, 3) in m)  # True
>>> print(datetime.date(1979, 8, 17) in m)  # False
```

--------------------------------

### Numeric Infinity Range

Source: https://python-ranges.readthedocs.io/en/latest/about.html

Demonstrates how infinity conforms to IEEE 754 for numeric types. Shows a range with inclusive start and exclusive end, including negative infinity.

```python
r = Range(include_start=True, include_end=False)
>>> print(r)  # [-inf, inf)
>>> print(float('-inf') in r)  # True
>>> print(float('inf') in r)  # False
```

--------------------------------

### Constructing RangeSet Instances

Source: https://python-ranges.readthedocs.io/en/latest/set.html

Demonstrates various ways to initialize a RangeSet, including empty sets, sets from iterables, and sets with mixed Range and string representations.

```python
>>> a = RangeSet()  # empty RangeSet
>>> b = RangeSet([Range(0, 1), Range(2, 3), Range(4, 5)])  # single iterable as a positional argument
>>> c = RangeSet(Range(0, 1), Range(2, 3), Range(4, 5))   # multiple Ranges as positional arguments
>>> d = RangeSet("[0, 1)", ["[1.5, 2)", "[2.5, 3)"], "[4, 5]")  # multiple positional arguments, one is an iterable
```

--------------------------------

### RangeDict with an infinite range

Source: https://python-ranges.readthedocs.io/en/latest/dict.html

Demonstrates the behavior when a RangeDict is initialized with an infinite range. Subsequent additions of finite ranges can alter the infinite range's coverage.

```python
e = RangeDict({Range(include_end=True): "inquisition"})
print(e)  # {{[-inf, inf)}: inquisition}
print(e.get(None))  # inquisition
print(e.get(3))  # inquisition
print(e.get("holy"))  # inquisition
print(e.get("spanish"))  # inquisition

e[Range("a", "m")] = "grail"

print(e)  # {{[-inf, a), [m, inf)}: inquisition, {[a, m)}: grail}
print(e.get("spanish"))  # inquisition
print(e.get("holy"))  # grail
print(e.get(3))  # KeyError
print(e.get(None))  # KeyError
```

--------------------------------

### Create Range with Date and String Bounds

Source: https://python-ranges.readthedocs.io/en/latest/about.html

Demonstrates creating ranges with non-numeric types like dates and strings. Default infinite bounds can be used with these types.

```python
k = Range(start=datetime.date(1969, 10, 5))  # [1969-10-05, inf)   includes any date after 5/10/1969
l = Range(end="ni", include_end=True)  # [-inf, ni)   all strings lexicographically less than 'ni'
```

--------------------------------

### Create a RangeDict from a dictionary of Ranges

Source: https://python-ranges.readthedocs.io/en/latest/dict.html

Initialize a RangeDict using a dictionary where keys are Range objects and values are the corresponding data.

```python
c = RangeDict({
    Range('a', 'h'): "First third of the lowercase alphabet",
    Range('h', 'p'): "Second third of the lowercase alphabet",
    Range('p', '{'): "Final third of the lowercase alphabet",
})
print(c['brian'])  # First third of the lowercase alphabet
print(c['king arthur'])  # Second third of the lowercase alphabet
print(c['python'])  # Final third of the lowercase alphabet
```

--------------------------------

### Create an empty RangeDict

Source: https://python-ranges.readthedocs.io/en/latest/dict.html

An empty RangeDict can be initialized without any arguments.

```python
a = RangeDict()
```

--------------------------------

### Create a RangeDict from another RangeDict

Source: https://python-ranges.readthedocs.io/en/latest/dict.html

A new RangeDict can be created as a copy of an existing one.

```python
b = RangeDict(a)
```

--------------------------------

### Create a Default Range

Source: https://python-ranges.readthedocs.io/en/latest/about.html

Constructs a Range object representing a range from negative infinity to positive infinity. This is a copy of an existing Range object.

```python
a = Range()   # range from -infinity to +infinity (see point #4 for how "infinity" works here)
b = Range(a)  # copy of a
```

--------------------------------

### Default Infinite Range

Source: https://python-ranges.readthedocs.io/en/latest/about.html

Creates a Range with default infinite bounds and inclusive end. This range contains all possible values for its type.

```python
q = Range(include_end=True)
>>> print(q)  # [-inf, inf]
>>> print(0 in q)  # True
>>> print(1 in q)  # True
>>> print(-99e99 in q)  # True
>>> print("one" in q)  # True
>>> print(datetime.date(1975, 3, 14) in q)  # True
>>> print(None in q)  # True
```

--------------------------------

### RangeSet Construction with Nested Iterables

Source: https://python-ranges.readthedocs.io/en/latest/set.html

Illustrates that nested iterables are not supported when constructing a RangeSet and will result in a ValueError.

```python
>>> e = RangeSet([[Range(0, 1), Range(2, 3)], [Range(4, 5), Range(6, 7)]])
```

--------------------------------

### RangeSet Combining Overlapping Ranges

Source: https://python-ranges.readthedocs.io/en/latest/set.html

Shows how a RangeSet automatically combines overlapping or adjacent ranges into a single, larger range during initialization.

```python
>>> f = RangeSet("[0, 3]", "[2, 4)", "[5, 6]")
>>> str(f) == "{[0, 4), [5, 6]}"
```

--------------------------------

### Using Identity Comparison in RangeDict

Source: https://python-ranges.readthedocs.io/en/latest/dict.html

Construct a RangeDict with identity=True to use `is` instead of `==` for comparing range keys with the same associated value, preventing unintended coalescing.

```python
>>> # `{3} is {3}` is False, so the two ranges don't coalesce
>>> g = RangeDict({Range(1, 2): {3}, Range(4, 5): {3}}, identity=True)
>>> print(g)  # {{[1, 2)}: {3}, {[4, 5)}: {3}}
```

--------------------------------

### RangeDict with shared mutable values

Source: https://python-ranges.readthedocs.io/en/latest/dict.html

Illustrates how RangeDict handles shared mutable values. Modifications to a mutable value through one range affect all ranges pointing to the same object.

```python
# [{3}] == [{3}] is True, so the two ranges are made to point to the same object
f = RangeDict({Range(1, 2): {3}, Range(4, 5): {3}})
print(f)  # {{[1, 2), [4, 5)}: {3}}

# f[1] returns the {3}. When |= is used, this object changes to {3, 4}
f[Range(1, 2)] |= {4}
# since the entire rangeset is pointing at the same object, the entire range changes
print(f)  # {{[1, 2), [4, 5)}: {3, 4}}
```

--------------------------------

### Create a RangeDict from an iterable of 2-tuples

Source: https://python-ranges.readthedocs.io/en/latest/dict.html

Similar to a regular dictionary, a RangeDict can be constructed from an iterable of (Range, value) tuples.

```python
d = RangeDict([
    (Range('A', 'H'), "First third of the uppercase alphabet"),
    (Range('H', 'P'), "Second third of the uppercase alphabet"),
    (Range('P', '['), "Final third of the uppercase alphabet"),
])
```

--------------------------------

### Avoiding Mutation Issues in RangeDict

Source: https://python-ranges.readthedocs.io/en/latest/dict.html

To avoid mutation problems, do not mutate mutable values that multiple range keys may refer to. Instead, use non-mutative operations like the union operator `|`.

```python
>>> h = RangeDict({Range(1, 2): {3}, Range(4, 5): {3}})
>>> print(h)  # {{[1, 2), [4, 5)}: {3}}
>>> h[Range(1, 2)] = h[Range(1, 2)] | {4}
>>> print(h)  # {{[4, 5)}: {3}, {[1, 2)}: {3, 4}}
```

--------------------------------

### Range with NaN Check

Source: https://python-ranges.readthedocs.io/en/latest/about.html

Shows that NaN (Not a Number) is not considered to be within the default infinite range for numeric types.

```python
>>> print(float('nan') in q)  # False
```
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