Boston Python Workshop 3/Data types

Numbers: integers and floats

Math: addition, subtraction, multiplication, division

addition: 2 + 2
subtraction: 0 - 2
multiplication: 2 * 3
division:

>>> 4 / 2
2
>>> 1 / 2
0

Integer divison produces an integer. You need a number that knows about the decimal point to get a decimal out of division:

>>> 1.0 / 2
0.5
>>> float(1) / 2
0.5

Types

>>> type(1)
<type 'int'>
>>> type(1.0)
<type 'float'>

Strings

>>> "Hello"
'Hello'

String concatenation

>>> print "Hello" + "World"
HelloWorld

Printing strings

>>> print "Hello"
Hello
>>> print "Hello", "World"
Hello World
>>> print "Hello", "World", 1
Hello World 1

Types

>>> type("Hello")
<type 'str'>

Booleans

>>> True
True
>>> False
False

Containment

>>> "H" in "Hello" True >>> "X" in "Hello" >>> "a" in ["a", "b", "c"] True >>> "x" in ["a", "b", "c"] False

"a" not in "abcde"

"Perl" not in "Boston Python Workshop"

Equality

>>> 0 == 0 True >>> 0 == 1 False

"a" != "a"

"a" != "A"

<, <=, >, and >= have the same meaning as in math class:

1 > 0

2 >= 3

-1 < 0

.5 <= 1