PCEP

Python Certified Entry-Level Programmer

What type of language is python

An interpreted language

Interpreted language

Code that is translated one line/instruction at a time.

Is compilation or interpretation typically faster?

Translated compiled code tends to run faster, whereas the compilation itself takes longer.

Does the end-user need a compiler?

No

Does the end-user need an interpreter?

Yes

How is compiled code stored?

It is stored in machine language

How is interpreted code stored?

In the programming language

Where can python functions come from?

They can be built into the language, be user defined, or imported from modules

Can several things occur on the same line

NO

What happens when you dont pass arguments to print()

When you don't pass arguments to print(), it will just output a new line. You can also use the escape character \n.

How do you print a backslash in a print statement

Double it up, \

How do you print quotation marks in a print statement?

print(' " ')

What is a keyword argument

An argument unaffected by its position

What are the keyword arguments for the print statement

end, sep

Where do keyword arguments go?

After the positional argument

What is a positional argument

An argument that is dictated by its position

What is a literal

A literal is a sequence of characters used in a program to represent a constant value.

Is a char or string a literal in python?

NO

Python literals

integer, floating point. An int has no dots.

Can you use underscores in a literal?

Yes

Booleans

True 1, False 0

How to determine int or float in arithmetic?

When both arguments are integers, the result is an int. If any arguments are floats, the end result will be a float.

Integer division

An operation that divides one integer by another and yields an integer. Integer division yields only the whole number of times that the numerator is divisible by the denominator and DISCARDS ANY REMAINDER

Binding of an operator

the order of computations performed by operators with equivalent precedence

Only right binding operator

Exponentiation, **

Variable naming rules

Cannot be a keyword

Must begin with a letter

Can contain letters, digits, and underscores

Case-sensitive

Comments in python

#

How can you save input

Assign it to a variable

Can you concatenate strings

Yes, with +

Can you concatenate strings and integers

NO

How do you replicate strings

StringA * 10 or 10 * StringA

What happens if you multiply a string by a number less than or equal to0

The string will be null

String typecast

str()

Python follows PEMDAS.

True

If statement

An if keyword is followed by an expression which evaluates to a boolean. All code for this statement is indented, indicating that it falls within this statement.

Else statement

An else statement is the same thing, else followed by a colon. These statements can be nested if indentations are performed properly.

Elif statement

The elif statement is an else if, and if the first if does NOT evaluate to true, than the elif condition will be checked

How many else statements can you have for an if block

zero or one

max()

Accepts multiple arguments, returns the highest value argument

min()

accepts multiple arguments, returns least value argument

While loop

A while loop will repeat a series of statements for as long as a certain condition evaluates to true. Recall that 1 is true and 0 is false, so if arithmetic operations evaluate to either 1 or 0, that works as true or false!

While else branch

A while loop can be followed by an else branch that will execute NO MATTER WHAT

Multi-line printing

Three apostrophes

Are strings a sequence type

Yes

Can strings be sliced

Yes, they are a sequence type

for loop

The for loop opens with the "for" keyword. The variable following is the control variable of the loop. The control variable automatically counts iterations of the loop. The control variable is followed by the "in" keyword and the range() function.

range()

If passed one argument, it will start from zero and count up to, but not including, the passed argument

If passed two arguments, itll count from the first to the second

If passed three arguments, itll count from the first to the second with the increment specified by the third argument.

Does range() accept float values

No, the range() function only accepts integers.

break

Exits the loop completely, and does not resume on the next iteration

continue

exits current iteration and begins the next iteration

For else branch

The else branch will execute NO MATTER WHAT. The only case in which it wouldnt is if a break statement executed before the else was reached.

bitwise AND

argA & argB

bitwise OR

argA | argB

bitwise NOT

~argA

bitwise XOR

argA ^ argB

Can bitwise logic be passed floats?

NO. ONLY INTEGERS.

Lists

Lists are like arrays in Java, except they are mutable. Lists can store a sequence of values.

Can list store different data types

Yes

Are lists indexed?

Yes, zero-based.

List initialization

myList = [1, 2, 3]

List index of -1

An index of -1 would mean the last element, -2 the element before that, and so on.

Method

a method is owned by the data it works for while a function belongs to the whole code.

myList.append(arg)

myList.insert(index, arg)

Function

Does not belong to any data, but rather, the whole code. A function does not belong to any data, it gets data, may create new data, and typically produces a result.

Swapping values

var1, var2 = var2, var1

list.sort()

method that sorts elements in list

list.reverse()

Reverse the elements of the list, in place.

listA = listB

Creates two variables for the same list

listA = listB[:]

Copies listB values into list a

Slice [:]

Implicitly 0, -1

Used to retrieve portions of sequence data types

del myList[0:3]

Would delete the first 4 elements of myList

in/not in

will check if an element is or is not present in a data structure (or the range function)

Filling a list with a for loop

myList = [x**2 for x in range(10)]

2-D list with a for loop

A 2-D list is a list within a list. Assume EMPTY is a predefined symbol, then:

board = [[EMPTY for i in range(8)] for j in range(8)]

Function definition

def myFunction(parameters):

code

Where does a parameter exist

ONLY in the function

Where is a parameter defined

In the parentheses

When is a value given to a parameter

When arguments are passed to it during invocation

Parameter vs argument scope

Parameters live inside of the functions while arguments live outside of the function.

Positional arguments

Passed by the order in which they appear

Keyword arguments

Must come AFTER positional arguments, explicitly stated.

Default parameter values

def myFuncton(a = 0):

If a parameter has a default does it NEED to be initialized

No, but it still can be

How do you return

Use the return keyword, and if you follow with an argument, that value will be returned.

Can you return nothing?

Yes, it is of type None

What can be done with the None keyword

It can be assigned to variables

It can be compared to variables

It can be returned from functions

Scope

Where in the program the variable is accessible

Scope of variable in function

Only within that function

Scope of variable outside of functions

The entire program

Scope of global variables

The entire program

Function-variable interaction

Changing a parameter's value will not automatically change the argument, as an argument will pass its value and not its reference