Exam 1

Question 1

What is a “program”

Answer 1

An algorithm to accomplish a task

Question 2

What is an “IDE”

Answer 2

Integrated Development Environment:
A compiler like spyder

Question 3

Quality assurance

Answer 3

how someting is checked to make sure it works as it is supposed to

Question 4

what is a unit test?

Answer 4

Software test that focuses on components of a program

Question 5

What is a test suite and a test runner

Answer 5

collection of test cases to run a single job with different test scenarios
Test runner: tool that is used to run tests and export results

Question 6

t or f:

Answer 6

false, it should contain only one assertion statement

Question 7

what is TDD

Answer 7

test driven development:
development where software requirements are converted tot est cases before software is fully developed

Question 8

what is pseudocode, why helpful

Answer 8

pseudocode is informal way of programming that does not require strict language syntax
can be helpful cuz more understandable

Question 9

What is a module, why helpful

Answer 9

a file that defines a collection of useful functions and variables, usually have a common theme or purpose
helpful so no need to redefine functions or variables every time

Question 10

what is a statement in a program

Answer 10

a command in a program that a computer understands

Question 11

what is an expression

Answer 11

value or anything that executes and becomes a value

Question 12

what are the rules for a valid variable name

Answer 12

1) start with a letter or underscore
2) only made of letters numbers or underscores
3) capitalized letters matter

Question 13

is a==A

Answer 13

no

Question 14

why is x = x**2 always valid

Answer 14

the expression updates x

Question 15

what is an operand

Answer 15

term used to describe the data or values that are operated on by an operater

Question 16

name three types and describe each of them

Answer 16

1) numeric (int, float, complex)
2) text sequence (string) words
3) sequence: list and range
4) binary sequence
5) plot: graphical representation of numeric data
etc…….

Question 17

binary operator?

Answer 17

operators that require two operands at least eg +, -, *

Question 18

unary operator?

Answer 18

operators that require one operand
only needs one operand: negative or positive

Question 19

what does = do?

Answer 19

assigns a value to a variable

Question 20

what does == do

Answer 20

compares two values to determine if they’re equal

Question 21

what does % do

Answer 21

output is the remainder

Question 22

waht does // do

Answer 22

divides and returns only integer result
eg -8//3 is -3 because answer is -2.67777… so rounds up

Question 23

what will -8/3 calculate to

Answer 23

-3

Question 24

what will 8%-3 calculate to

Answer 24

will be -3 because because will return a value that is the same sign as the denominator
goes in opp direction
3 * 3 = 9 so remainder is -1
3*2 = 6 so remainder is +2

Question 25

relational operator?

Answer 25

operator that compares two values and returns true or false

Question 26

what is the order of precedence in decreasing of the and, not, or

Answer 26

1) not 2) and 3) or

Question 27

do arithmetic or relational operators have higher precedence

Answer 27

arithmetic

Question 28

t or f: all realtional operations have the same precedence

Answer 28

true

Question 29

what are lists

Answer 29

array... usually composed of same variables

Question 30

how do you express the third elemnt in a list

Answer 30

list[2]

Question 31

how would you express second to last element in a list

Answer 31

if list is n long, list[n-2] or list[-2]

Question 32

given a list x = [1, 2, 3,4 ,5], what will x[2::2] return

Answer 32

will return [3, 5] starts from x[2] and has step of 2

Question 33

what does import do

Answer 33

import is used to give access to different python moduels

Question 34

what does len() do

Answer 34

gives the elngth of an object, number of items in a list

Question 35

what does .append() do

Answer 35

adds whatever is inside () to the end of existing array

Question 36

what makes up np.linspace() command

Answer 36

np.linspace(start, stop, how many samples to generate).astype(int or float) int: determines whether elements are floats or integers

Question 37

what are three attrinbutes of a numpy array

Answer 37

1. always homogenous (same data type) 2. optimized for numerical and scientific computation 3. can be manipulated using mathematical functions like linear algebra etc 4. consumes less memory

Question 38

deep copy vs shallow copy?

Answer 38

shallow: constructs new compound object and inserts references into the array deep: recursively inserts copies of the og into each entry

Question 39

Why indent?

Answer 39

indicates a block of code

Question 40

how many spaces in a single indent?

Answer 40

4 spaces

Question 41

What is the difference between a parameter and an argument?

Answer 41

A parameter is a placeholder for a certain type of value while an argument defines the parameter's value

Question 42

If a function does not need to return anything, what does the return expression look like

Answer 42

no return statement

Question 43

List convention for docstring

Answer 43

1) first line should be short concise function summary 2) The first line should be a phrase ending in a period 3)Indent lines consistently 4) Separate lines with a blank line when needed

Question 44

what is PEP

Answer 44

document where new features in python can be proposed

Question 45

Abs Error vs Rel Error?

Answer 45

Abs error is the difference between measured eerror and true error Rel error is the absoute error divided by true value (percentage)

Question 46

What is the hidden bit?

Answer 46

gives the sign of the number

Question 47

what is machine epsilon?

Answer 47

The difference between 1.0 and the next larger representable number

Question 48

in double precision IEEE-754 , how many binary bits are used to store a real number

Answer 48

64 bits 1 bit for sign, 11 bits for exponent, and 52 bits for significant

Question 49

What information does the sign bit give

Answer 49

gives the sign of the number

Question 50

what information does the exponent give

Answer 50

Scaling factor, determines how many decimal places

Question 51

What informaiton does the significand give?

Answer 51

fractional values, amt of sig figs

Question 52

What does assert do?

Answer 52

Used to test a condition assert condition, message if condition is not true, message is raised with assertion error

Question 53

what is assert best used for?

Answer 53

good for debugging and teesting assumptions bad for data validation

Question 54

what does [0:2] do

Answer 54

in a list it would slice out all entries past 1. This is because start is inclusive while stop is excusive

Question 55

Metaphor for and

Answer 55

switches in series

Question 56

Metaphor for or

Answer 56

switches in parallel

Question 57

The inverse of an upper triangular matrix is also an__

Answer 57

upper triangular matrix

Question 58

What is (AB)^-1 equal to

Answer 58

B^-1 * A^-1

Question 59

T or f: an LU decomp always exists if the matrix is square invertible without altering the matrix

Answer 59

False

Question 60

if Q is an invertible square matrixwhat is Q.T * Q equivalent to

Answer 60

I