diff options
Diffstat (limited to 'python3.html.markdown')
-rw-r--r-- | python3.html.markdown | 33 |
1 files changed, 24 insertions, 9 deletions
diff --git a/python3.html.markdown b/python3.html.markdown index b378a8c6..4d5bb3ae 100644 --- a/python3.html.markdown +++ b/python3.html.markdown @@ -72,15 +72,24 @@ not False # => True True and False # => False False or True # => True -# Note using Bool operators with ints -# False is 0 and True is 1 +# True and False are actually 1 and 0 but with different keywords +True + True # => 2 +True * 8 # => 8 +False - 5 # => -5 + +# Comparison operators look at the numerical value of True and False +0 == False # => True +1 == True # => True +2 == True # => False +-5 != False # => True + +# Using boolean logical operators on ints casts them to booleans for evaluation, but their non-cast value is returned # Don't mix up with bool(ints) and bitwise and/or (&,|) +bool(0) # => False +bool(4) # => True +bool(-6) # => True 0 and 2 # => 0 -5 or 0 # => -5 -0 == False # => True -2 == True # => False -1 == True # => True --5 != False != True #=> True # Equality is == 1 == 1 # => True @@ -96,7 +105,10 @@ False or True # => True 2 <= 2 # => True 2 >= 2 # => True -# Comparisons can be chained! +# Seeing whether a value is in a range +1 < 2 and 2 < 3 # => True +2 < 3 and 3 < 2 # => False +# Chaining makes this look nicer 1 < 2 < 3 # => True 2 < 3 < 2 # => False @@ -139,9 +151,11 @@ len("This is a string") # => 16 # still use the old style of formatting: "%s can be %s the %s way" % ("Strings", "interpolated", "old") # => "Strings can be interpolated the old way" -# You can also format using f-strings or formatted string literals +# You can also format using f-strings or formatted string literals (in Python 3.6+) name = "Reiko" f"She said her name is {name}." # => "She said her name is Reiko" +# You can basically put any Python statement inside the braces and it will be output in the string. +f"{name} is {len(name)} characters long." # None is an object @@ -279,7 +293,8 @@ a, b, c = (1, 2, 3) # a is now 1, b is now 2 and c is now 3 # You can also do extended unpacking a, *b, c = (1, 2, 3, 4) # a is now 1, b is now [2, 3] and c is now 4 # Tuples are created by default if you leave out the parentheses -d, e, f = 4, 5, 6 +d, e, f = 4, 5, 6 # tuple 4, 5, 6 is unpacked into variables d, e and f +# respectively such that d = 4, e = 5 and f = 6 # Now look how easy it is to swap two values e, d = d, e # d is now 5 and e is now 4 |