Basics of Types

Question 1

What are the three basic number types and their Python shorthand

Answer 1

Integers = int
Real numbers = float
Complex numbers = complex

Question 2

How do you find out the type of an object?

Answer 2

Function: type(obj)

Question 3

What is a string and what is the Python shorthand?

Answer 3

String is a sequence of characters, normally enclosed in single or double quotation marks.

Question 4

How do you escape characters in strings?

Answer 4

Backslash - \
Eg,
» print(“My name is "Levi"”)
My name is “Levi”

Question 5

How do you insert a tab into a string?

Answer 5

\t

Question 6

How do you insert a newline into a string?

Answer 6

\n

Question 7

How can you avoid having to escape special characters?

Answer 7

Triple quotation marks (‘’’ or “””)

Question 8

Where the three main/basic binary operators that can be applied to strings?

Answer 8

+ (concatenation)
* (repeat string N times)
in (subset of?)

Question 9

Give an example of the ‘in’ binary operator for strings?

Answer 9

> > print(‘z’ in ‘Zebra’)

True

Question 10

How does assignment work?

Answer 10

>>> a = 1
>>> print(a)
1
The RHS is evaluated and then assigned to the LHS, allowing self-referential assignment:
>>> a = a + 2
>>> print(a)
3

Question 11

What is ‘stacking’ assignment variables?

Answer 11

>>> a = b = c = 2
>>> print(a)
2
>>> print(b)
2
>>> print(c)
2
>>> a = b = c = a + b + c
>>> print(a," ",b," ",c)
6 6 6

Question 12

What characters can a variable name start with?

Answer 12

(a-zA-Z) or underscore (_)

Question 13

What characters can a variable name contain?

Answer 13

Alphanumeric (0-9a-zA-Z) and underscore (_)

Question 14

Does case matter when naming variables?

Answer 14

Yes, apple != Apple, they are different variables

Question 15

What are reserved words?

Answer 15

Operators, literals and built-in functions that cannot be used for variable names (eg in, print, not, str)

Question 16

Calculate the ith Fibonacci number using only three variables.

Answer 16

a = 1
b = 2
c = a + b
Redefine a and b sequentially

Question 17

How do we ‘cast’ a literal or variable as a different type?

Answer 17

Use functions of the same name as the type into which we want to cast: int(), float(), str(), complex()…

Question 18

What does abs() do?

Answer 18

Returns the absolute value of the operand

Question 19

What does len() do?

Answer 19

Return the length of the ITERABLE operand
Eg,
>>> len('string')
6
>>> len([1,2,3])
3

Question 20

Given num containing an int, calculate the number of digits in it.

Answer 20

> > > len(str(num))

Question 21

What are the four basic types in this deck?

Answer 21

str, int, float, complex

Question 22

How are string specified?

Answer 22

Using single or double quotation marks (‘ or “)

Question 23

What is the difference between a literal and a variable?

Answer 23

A literal is fixed, a variable is not. A variable is a stored memory location for an assigned value.