Unit 2 Recitation

a name paired with a value

variable

How do we assign a variable a value?

=

• a = 4, b = 2, c = a * b

Variable Naming Conventions

• Only contain ______, _____, & ______

• First letter must be a _____or______

• letters, numbers, and underscores

• letter or underscore

Integer

whole number w/o decimal; positive, negative, or 0

Floats

• number with decimal; positive, negative, or 0.0

Strings

sequence of any characters enclosed in quotation marks; treated like text

Booleans (bool)

True (1) or False (0); used for evaluating statement (is something true or false?)

type()

returns a variable’s data type

Ex: print(type(my_num)) —> <class ‘int’>

Different data types can be interconverted…with some important notes.

• learn conversion rules b/w data types

Different data types can be interconverted…with some important notes.

• learn conversion rules b/w data types

Mathematical operators

• Function:

• Ex: (7)

• Function: allow you to carry out math operations

• Ex: +, -, / (float division), *, ** (exponentiation), // (floor division), % (remainder/modulus),

If one or more numbers in a floor division operation is a float, the operation will return a _____.

float

Self-assignment

When a variable is declared and then reassigned to the variable via a calculation

• Ex: my_var = 2 / my_var = my_var + 7 (my_var += 7)

Incrementing

Reassigning a variable to itself + 1

Ex: my_var += 1

3 Types of Logical Operators

Relational, Set, Boolean

Relational

checks relationship b/w variables

• Ex: <, >, ==, <=, >=

Set

checks if a value is in a set

• Ex: in

Boolean

And, Or, Not

String Comparisons

• Strings are compared lexographically via ASCII

• Oder: num < uppercase < lowercase

• print(“3”<“THREE”<“three”) -> True

Review Truth Tables

Review Truth Tables