# 3.3. Logic Bool¶

## 3.3.1. Rationale¶

• True - Positive value

• False - Negative value

## 3.3.2. Syntax¶

• First letter capitalized, other are lower cased

>>> data = True
>>> data = False

>>> data = true
Traceback (most recent call last):
NameError: name 'true' is not defined

>>> data = TRUE
Traceback (most recent call last):
NameError: name 'TRUE' is not defined


## 3.3.3. Type Casting¶

• Builtin function bool() converts argument to bool

>>> bool(True)
True
>>>
>>> bool(False)
False
>>>
>>> bool(1)
True
>>>
>>> bool(0)
False

>>> bool(1)
True
>>>
>>> bool(2)
True
>>>
>>> bool(3)
True
>>>
>>> bool(-1)
True
>>>
>>> bool(-2)
True
>>>
>>> bool(-3)
True
>>>
>>> bool(1.0)
True
>>>
>>> bool('Jan Twardowski')
True


## 3.3.4. Negative values¶

>>> bool(0)
False
>>>
>>> bool(0.0)
False
>>>
>>> bool(0+0j)
False
>>>
>>> bool(0.0+0.0j)
False
>>>
>>> bool(False)
False
>>>
>>> bool(None)
False
>>>
>>> bool('')
False
>>>
>>> bool(())
False
>>>
>>> bool([])
False
>>>
>>> bool({})
False

>>> bool(int())
False
>>>
>>> bool(float())
False
>>>
>>> bool(complex())
False
>>>
>>> bool(bool())
False
>>>
>>> bool(str())
False
>>>
>>> bool(tuple())
False
>>>
>>> bool(list())
False
>>>
>>> bool(dict())
False
>>>
>>> bool(set())
False


## 3.3.5. Comparison¶

• x < y - Less than

• x <= y - Less or equal

• x > y - Greater than

• x >= y - Greater or equal

• == - Equals

• != - Not Equals

>>> 10 < 2
False
>>>
>>> 10 <= 2
False
>>>
>>> 10 > 2
True
>>>
>>> 10 >= 2
True
>>>
>>> 10 == 2
False
>>>
>>> 10 != 2
True

>>> x = 1
>>> y = 2
>>>
>>>
>>> x == 1
True
>>>
>>> y == 2
True
>>>
>>> x == y
False
>>>
>>> x != y
True


## 3.3.6. Conjunction¶

Definition:

1 & 1 -> 1
1 & 0 -> 0
0 & 1 -> 0
0 & 0 -> 0


Example:

>>> True and True
True
>>>
>>> True and False
False
>>>
>>> False and True
False
>>>
>>> False and False
False


## 3.3.7. Use Case - 0x01¶

>>> firstname = 'Mark'
>>> lastname = 'Watney'
>>>
>>>
>>> firstname == 'Mark' and lastname == 'Watney'
True
>>>
>>> firstname == 'Mark'
True
>>>
>>> lastname == 'Watney'
True
>>>
>>> True and True
True


## 3.3.8. Use Case - 0x02¶

>>> firstname = 'Mark'
>>> lastname = 'Watney'
>>>
>>>
>>> firstname == 'Mark' and lastname == 'Twardowski'
False
>>>
>>> firstname == 'Mark'
True
>>>
>>> lastname == 'Twardowski'
False
>>>
>>> True and False
False


## 3.3.9. Disjunction¶

Definition:

1 | 1 -> 1
1 | 0 -> 1
0 | 1 -> 1
0 | 0 -> 0


Example:

>>> True or True
True
>>>
>>> True or False
True
>>>
>>> False or True
True
>>>
>>> False or False
False


## 3.3.10. Use Case - 0x01¶

>>> name = 'Mark Watney'
>>>
>>> name == 'Mark Watney' or name == 'Melissa Lewis'
True


## 3.3.11. Use Case - 0x02¶

>>> name = 'Mark Watney'
>>>
>>>
>>> name == 'Mark Watney'
True
>>>
>>> name == 'Melissa Lewis'
False
>>>
>>> True or False
True


## 3.3.12. Boolean Algebra¶

Example:

>>> True and True or False
True
>>>
>>> False and False or True
True

>>> (True and True) or False
True
>>>
>>> True and (True or False)
True

>>> True and False or False
False
>>>
>>> True and (False or False)
False


## 3.3.13. Use Case - 0x01¶

>>> firstname = 'Mark'
>>> lastname = 'Watney'
>>>
>>>
>>> (firstname == 'Mark' and lastname == 'Watney') \
...     or (firstname == 'Melissa' and lastname == 'Lewis') \
...     or (firstname == 'Rick' and lastname == 'Martinez')
True


## 3.3.14. Use Case - 0x02¶

>>> firstname = 'Mark'
>>> lastname = 'Watney'
>>>
>>>
>>> firstname == 'Mark' and lastname == 'Watney'
True
>>>
>>> firstname == 'Melissa' and lastname == 'Lewis'
False
>>>
>>> firstname == 'Rick' and lastname == 'Martinez'
False
>>>
>>> True or False or False
True


## 3.3.15. Built-in Functions¶

• type() - Checks type of an object

• isinstance(a, x) - If a is instance of x

• isinstance(a, (x,y)) - If a is instance of x or y

>>> type(True)
<class 'bool'>
>>>
>>> type(False)
<class 'bool'>

>>> isinstance(1, bool)
False
>>>
>>> isinstance(1, int)
True
>>>
>>> isinstance(1, float)
False

>>> isinstance(1.23, bool)
False
>>>
>>> isinstance(1.23, int)
False
>>>
>>> isinstance(1.23, float)
True

>>> isinstance(True, bool)
True
>>>
>>> isinstance(True, int)
True
>>>
>>> isinstance(True, float)
False
>>>
>>> isinstance(False, bool)
True
>>>
>>> isinstance(False, int)
True
>>>
>>> isinstance(False, float)
False


## 3.3.16. Assignments¶

"""
* Assignment: Type Bool True or False
* Required: yes
* Complexity: easy
* Lines of code: 16 lines
* Time: 5 min

English:
1. Which variables are True?
2. Which variables are False?
3. Run doctests - all must succeed

Polish:
1. Które zmienne są True?
2. Które zmienne są False?
3. Uruchom doctesty - wszystkie muszą się powieść

Tests:
>>> import sys; sys.tracebacklimit = 0

>>> assert a is not Ellipsis, 'Assign result to variable: a'
>>> assert b is not Ellipsis, 'Assign result to variable: b'
>>> assert c is not Ellipsis, 'Assign result to variable: c'
>>> assert d is not Ellipsis, 'Assign result to variable: d'
>>> assert e is not Ellipsis, 'Assign result to variable: e'
>>> assert f is not Ellipsis, 'Assign result to variable: f'
>>> assert g is not Ellipsis, 'Assign result to variable: g'
>>> assert h is not Ellipsis, 'Assign result to variable: h'
>>> assert i is not Ellipsis, 'Assign result to variable: i'
>>> assert j is not Ellipsis, 'Assign result to variable: j'
>>> assert k is not Ellipsis, 'Assign result to variable: k'
>>> assert l is not Ellipsis, 'Assign result to variable: l'
>>> assert m is not Ellipsis, 'Assign result to variable: m'
>>> assert n is not Ellipsis, 'Assign result to variable: n'
>>> assert o is not Ellipsis, 'Assign result to variable: o'
>>> assert n is not Ellipsis, 'Assign result to variable: n'
>>> assert p is not Ellipsis, 'Assign result to variable: p'
>>> assert q is not Ellipsis, 'Assign result to variable: q'
>>> assert type(a) is bool, 'Variable a has invalid type, should be bool'
>>> assert type(b) is bool, 'Variable b has invalid type, should be bool'
>>> assert type(c) is bool, 'Variable c has invalid type, should be bool'
>>> assert type(d) is bool, 'Variable d has invalid type, should be bool'
>>> assert type(e) is bool, 'Variable e has invalid type, should be bool'
>>> assert type(f) is bool, 'Variable f has invalid type, should be bool'
>>> assert type(g) is bool, 'Variable g has invalid type, should be bool'
>>> assert type(h) is bool, 'Variable h has invalid type, should be bool'
>>> assert type(i) is bool, 'Variable i has invalid type, should be bool'
>>> assert type(j) is bool, 'Variable j has invalid type, should be bool'
>>> assert type(k) is bool, 'Variable k has invalid type, should be bool'
>>> assert type(l) is bool, 'Variable l has invalid type, should be bool'
>>> assert type(m) is bool, 'Variable m has invalid type, should be bool'
>>> assert type(n) is bool, 'Variable n has invalid type, should be bool'
>>> assert type(o) is bool, 'Variable o has invalid type, should be bool'
>>> assert type(p) is bool, 'Variable p has invalid type, should be bool'
>>> assert type(q) is bool, 'Variable q has invalid type, should be bool'

>>> a
False
>>> b
True
>>> c
False
>>> d
False
>>> e
False
>>> f
False
>>> g
True
>>> h
True
>>> i
True
>>> j
True
>>> k
False
>>> l
True
>>> m
False
>>> n
False
>>> o
False
>>> p
True
>>> q
False
"""

a = bool(False)
b = bool(True)

c = bool(0)
d = bool(0.0)
e = bool(-0)
f = bool(-0.0)

g = bool('a')
h = bool('.')
i = bool('0')
j = bool('0.0')
k = bool('')
l = bool(' ')

m = bool(int('0'))
n = bool(float(str(-0)))

o = bool(-0.0 + 0.0j)
p = bool('-0.0+0.0j')
q = bool(complex('-0.0+0.0j'))


"""
* Assignment: Type Bool Simple
* Required: yes
* Complexity: easy
* Lines of code: 9 lines
* Time: 5 min

English:
1. What you need to put in expressions to get the expected outcome?
2. In place of ellipsis (...) insert only True or False
3. Run doctests - all must succeed

Polish:
1. Co należy podstawić w wyrażeniach aby otrzymać wartość oczekiwaną?
2. W miejsce trzech kropek (...) wstawiaj tylko True lub False
3. Uruchom doctesty - wszystkie muszą się powieść

Tests:
>>> import sys; sys.tracebacklimit = 0

>>> assert a is not Ellipsis, 'Assign result to variable: a'
>>> assert b is not Ellipsis, 'Assign result to variable: b'
>>> assert c is not Ellipsis, 'Assign result to variable: c'
>>> assert d is not Ellipsis, 'Assign result to variable: d'
>>> assert e is not Ellipsis, 'Assign result to variable: e'
>>> assert f is not Ellipsis, 'Assign result to variable: f'
>>> assert g is not Ellipsis, 'Assign result to variable: g'
>>> assert h is not Ellipsis, 'Assign result to variable: h'
>>> assert i is not Ellipsis, 'Assign result to variable: i'
>>> assert type(a) is bool, 'Variable a has invalid type, should be bool'
>>> assert type(b) is bool, 'Variable b has invalid type, should be bool'
>>> assert type(c) is bool, 'Variable c has invalid type, should be bool'
>>> assert type(d) is bool, 'Variable d has invalid type, should be bool'
>>> assert type(e) is bool, 'Variable e has invalid type, should be bool'
>>> assert type(f) is bool, 'Variable f has invalid type, should be bool'
>>> assert type(g) is bool, 'Variable g has invalid type, should be bool'
>>> assert type(h) is bool, 'Variable h has invalid type, should be bool'
>>> assert type(i) is bool, 'Variable i has invalid type, should be bool'

>>> bool(a)
True
>>> bool(b)
True
>>> bool(c)
False
>>> bool(d)
True
>>> bool(e)
True
>>> bool(f)
False
>>> bool(g)
True
>>> bool(h)
True
>>> bool(i)
False
"""

# bool: the expression result must be True
a = True == ...

# bool: the expression result must be True
b = True != ...

# bool: the expression result must be False
c = not ...

# bool: the expression result must be True
d = bool(...) == True

# bool: the expression result must be True
e = bool(...) == False

# bool: the expression result must be False
f = ... or ...

# bool: the expression result must be True
g = ... and ...

# bool: the expression result must be True
h = bool(bool(...) == ...) or False

# bool: the expression result must be False
i = bool(...) is not bool(False)