Python course: Boolean logic
This is a data type used to represent a situation that can assume only one out of two possibilities. It’s like the outcome of flipping a coin: it must be either head or tails. There’s no third option. Despite its simplicity, it’s a very useful data type that can help remove ambiguity and provide clarity and elegance to your programs.
The two possible values for a boolean are True or False.
# PART 1
print(1 > 2) # => False
print(1 < 2) # => True
print(2 >= 2) # => True
print(6 > 6) # => False
print(5 == 5) # => True
tricky = 1 == 1
print(tricky) # => True
# PART 2
print("ryan" == "kelly") # => False
print("ryan" == "ryan") # => True
print("ryan" != "kelly") # => True
print(["pam"] == ["pam"]) # => True
print(("michael", "jan") == ("michael", "holly")) # => False
# PART 3
def is_michael(name: str) -> bool:
return name == "michael"
print(is_michael("michael")) # => True
print(is_michael("stanley")) # => False
PART 1
This is a basic mathematical comparison between numbers using the operators greater than (>), less than (<), and greater than or equals (>=).
tricky
This can cause confusion sometimes, because the operator for assigning values (=) is very similar to the operator for equivalence (==). Here, the value of this variable is equal to the output of the operation 1 == 1 (which is True, since 1 is equal to 1). In this case, adding parentheses may improve readability. Feel free to write it as: tricky = (1 == 1). Read more about operators in the Operators post.
PART 2
The comparison works for strings and other data types as well. Notice that in print("ryan" != "kelly") I used the not equal operator (!=). In other words, it’s like asking: is “ryan” different than “kelly”? The answer is yes (True).
PART 3
This is a more realistic use case of a boolean. The is_michael() function returns the equality check between the name argument and the string “michael”. Where it returns True if name is equals to (==) “michael”. Otherwise, it returns False. There is not a third possibility!
Notice I didn’t need to explicitly write
TrueorFalseas return options. This is the elegance and simplicity that I mentioned earlier about booleans.
