Python

Question 1

Why Python to learn as a beginner?

Answer 1

It’s syntax is relatively simple and you don’t have to worry about things like static syntax and compilation time

Question 2

What is homebrew?

Answer 2

It is a package manager that helps us install software on our operating system

Question 3

Who created Python?

Answer 3

Guido Van Rossum in 1991

Question 4

What are some popular libraries?

Answer 4

NumPy, SciPy, BeautifulSoup, Scrapy, Twisted, Django

Question 5

How does Python know how to run code?

Answer 5

Indentation…tab or four spaces…DO NOT MIX UP

Question 6

How would you do Python for 1 to 255

Answer 6

def print1to255():
    for i in range(1, 256):
        print i

Question 7

Why version 2.7 and not 3.6?

Answer 7

Porting code over is easy, but going backwards is not so easy

Question 8

What is a web server?

Answer 8

A computer system that processes HTTP requests

Question 9

Why are companies using 2.7?

Answer 9

There are many reasons why this is the case, the primary being the expense of switching all of a company’s code base from one version to another

Question 10

What is the Python shell?

Answer 10

The python shell is a command line interface we can use to interact with the Python interpreter. Once activated, we can type some Python code and see the results immediately.

Question 11

If I divide 31/2 on the python shell command line, what is the result?

Answer 11

15, most programming languages treat integers (whole numbers) and floating point numbers, or floats (decimal numbers) differently. If you divid an integer by an integer, the result will always be an integer rounded down

Question 12

Do you need to utilize var to declare a variable in Python?

Answer 12

No

Question 13

What is a list in Python?

Answer 13

A list is an array

Question 14

How can we comment out code in Python?

Answer 14

Using either # for single line, or triple quotes (double or single) for multiple lines UNLESS it’s the first line of code.

Question 15

What are data types?

Answer 15

Data types refers to how the computer knows to classify information.

Question 16

What are primitive data types? What are the most common?

Answer 16

Are the basic building blocks of a language.
Boolean values - Assess the truth value of something. It has only two values: True and False
Numbers - Integers (whole numbers), floating point numbers, and complex numbers
Strings - a text literal. Most pages in the web work with strings quite often

Question 17

What are composite data types?

Answer 17

Collections composed of the above primitive types.
Tuples - A type of data that is immutable (can’t be modified after its creation) and can hold a group of values. Tuples can contain mixed data types.
Lists - A type of data that is mutable and can hold a group of values. Usually meant to store a collection of related data.
Dictionaries - A group of key-value pairs. Dictionary elements are indexed by unique keys which are used to access values.

Question 18

Indentation, explain it’s significance

Answer 18

Python has no brackets, braces, or keywords to indicate the start and end of certain code blocks such as functions, if statements, and loops. The only delimited is the colon :

Question 19

What is the equivalent of function in python?

Answer 19

def

Question 20

How can you print a string with a variable?

Answer 20

print “my name is”, variable

print “my name is” + variable

Question 21

What is string interpolation?

Answer 21

Utilizing a method to inject variables into your string.

first_name = “Zen”
last_name = “Coder”
print “My name is {} {}”.format(first_name,last_name)

Question 22

What are the most commonly used string methods?

Answer 22

string. count(substring): returns number of occurrences of substring in string.
string. endswith(substring): returns a boolean based upon whether the last characters of string match substring.
string. find(substring): returns the index of the start of the first occurrence of substring within string.
string. isalnum(): returns boolean depending on whether the string’s length is > 0 and all characters are alphanumeric (letters and numbers only). Strings that include spaces and punctuation will return False for this method. Similar methods include .isalpha(), .isdigit(), .islower(), .isupper(), and so on. All return booleans.
string. join(list): returns a string that is all strings within our set (in this case a list) concatenated.
string. split(): returns a list of values where string is split at the given character. Without a parameter the default split is at every space.

Question 23

How would you add information to a list?

Answer 23

.append()

Question 24

What is the equivalent of array.slice(start, end not inclusive)?

Answer 24

x[1:4]

Question 25

what is the similar function to javascript .length?

Answer 25

len(sequence)…can be applied to all sequences, including tuples and strings

Question 26

What are some useful built-in functions for sequences?

Answer 26

Some built-in functions for sequences:
enumerate(sequence) used in a for loop context to return two-item-tuple for each item in the list indicating the index followed by the value at that index.

map(function, sequence) applies the function to every item in the sequence you pass in. Returns a list of the results.

min(sequence) returns the lowest value in a sequence.

sorted(sequence) returns a sorted sequence

Question 27

What is a type?

Answer 27

int, boolean, string, list,

when creating a dictionary, indentation requirements are not as strict

Question 28

for x in mydictionary: print x, mydictionary[x]

Answer 28

Dictionaries are good for more structure. Storing user information you can use a dictionary and it’s a lot easier

Question 29

What is a set?

Answer 29

a = {1,2,3,4,5} and you can subtract a set from another set