Section two - first app

Question 1

How do you show the type of something?

Answer 1

print(type(var))

Question 2

Show the amount of characters in something

Answer 2

len(variable)

Question 3

add an element to a list
What is this called?

Answer 3

list.append(“append with this”)

Method, it’s like a function but it’s attached to a data type (list, variable, etc)

Question 4

Capitalize the first lettter of the string variable

Capitalize the first letter in every word

Answer 4

These are the methods you attach

print(todo.capitalize())

todo.title()

Question 5

continuously print “Hello”

Answer 5

while True:
print(“Hello”)

Question 6

Create a program to enter a password

Answer 6

password = input(“Enter a password”)

while password != “pass123”
password = input(“Enter a password”)

print(“Correct”)

Question 7

Show all methods for objects
For instance, how do I find out how to capitalize a string?
Show more info on the method

Answer 7

CMD
python3
dir(str)
Methods are after the underscored stuff
help(str.capitalize)

You’ll notice here that it will output “capitalize()” which shows it takes not arguments.

Question 8

List functions like “print”

Answer 8

CMD
python3
import builtins
dir(builtins)
Lowercase are all functions
help(input)

Question 9

Create a case program

Answer 9

match user_action:
case “add”:
todo = input(“Enter a todo”)
todos.append(todo)
case “show”:
print(todos)

Question 10

Print list elements per line

Answer 10

for item in list:
print(item)

Question 11

If I want remove an ending space, what method would we use?

Answer 11

user_action.strip()

Question 12

What is python’s interpreter

Answer 12

cpython
python download
It’s an interpreter
interprets python to machine language

Question 13

you have created the below list
list = [‘a’, ‘b’, ‘c’]
you want to find the index of ‘b’
What command do you use?

Answer 13

list.index(‘b’)

Question 14

Strings are immutable so you can’t change them with
list[0][1] = “-“
instead, what would you use to change a period to a “-“

Answer 14

This will replace the string
list[1] = list.replace(“.”,”-“,1)
one means only change the first occurence of the dot.

Question 15

What is the immutable version of a list

Answer 15

tuple = (‘this’, ‘that’, ‘other’)

Question 16

how do you read the below explanation for a list method

pop(self, index=-1, /)
remove and return item at index (default last).

Answer 16

You put in an index number as the arguement, it will return the removed item.

It will show you what’s in slot in a list

-1 = default value of the argument
So if you enter nothing, it will be -1, the last item. This means you can actually go backwards through a list like this.

Question 17

Sort a list alphabetically

Answer 17

list.sort()
dir(list)
help(list.sort())

Question 18

word = “hello”
Replace the o for a period

Answer 18

word.replace(“o”, “.”)

Question 19

Store info from your program in a text file

What is the issue with this and how do we solve it?

Answer 19

Create a text file in the same directory as your program.

todos = []
todos.append(“cook”) + \n

Create a file object to write to “r” would be read.

file = open(‘todos.txt’, ‘w’)
file.writelines(todos) < - add the whole list “todos”

You might want to add a “+ \n” after your input to put a space in the file.

THIS WILL CREATE A NEW FILE EVERYTIME SO IT WILL DELETE THE OLD INFO WITH EVERY NEW ITERATION.

Instead add this prior to your “w” command and delete your list altogether

todo = input(‘enter a todo: ‘)
file = open(‘todos.txt’, ‘r’)
todos = file.readlines()

REMEMBER TO CLOSE FILE

file.close()
todos.append(todo)

Question 20

Write a simple string to a file instead of a list

Answer 20

file = open(‘text.txt’, ‘w’)
file.write(‘Hey this is your text!’)
file.read() <- instead of read lines if you want list form.

Question 21

What does it mean to exhaust file.read()

Answer 21

There is a CURSOR in a file that starts at the first item/object in the text file.
When you file.read(), it goes to the end, so if you try to file.read() again, it will output nothing.

Question 22

When adding an absolute path in windows, why do we need to add the “r” prior to the path?

Answer 22

r - raw
The reason for this is because certain symbols, like “" in python call a certain thing to happen. Like “\t” giving you a tab. To make sure it only reads it in text form, we add “r”

\n < - things like this are known as escape sequences

Question 23

We have content in one list, and text files in a another, how do we add the content to each of the text files

contents = [‘one’, ‘two’, ‘three’]

files = [‘one.txt’, ‘two.txt’, ‘three.txt’]

Answer 23

for content, files in zip(contents, filenames):
file = open(filename, ‘r’)
file.write()

THIS WON’T PRINT ON IT’S OWN

The structure would look like
[(‘one’, ‘one.txt’),(‘two’, ‘two.txt’),(‘three’, ‘three.txt’)]

If you were doing the below
x = zip(contents, filenames)
you could print this only by listing it’s elements
list(x)

Question 24

Create a multiline string in a variable

Answer 24

a = “this is a really” \
“I swear it is”

a = “"”This that
and the other”””

Question 25

What's a neat way to iterate items from a list into another one

Answer 25

list = [item.strip('\n') for item in todos]

Question 26

change fhe following to .txt files and dash in their name instead of a . without using a for loop. What is this known as? filename = ['1.doc', 1.report', '1.presentation']

Answer 26

list comprehension - create lists in [with a for loop here] filenames = [filename.replace('.', '-') + '.txt' for filename in filenames]

Question 27

Create a with statement to close your file. Why is this a better way to do things?

Answer 27

with open('todos.txt', 'r') as file: file = todos.readlines() If the program stops because of problems it will always close the file. Otherwise the file will never be closed which can cause problems. Use list comprehension here. This will create a new list and iterate through the items, placing them back in the new list: data = [item.strip() for item in data]

Question 28

If we wanted to know if the word 'add' was in: this = 'add user name' What expression would we use? What expression would we use if add and new were both acceptable What if you needed both What if you wanted to make sure 'and' wasn't in the variable?

Answer 28

if 'add' in this or 'new' in this or 'more' in this: print("True") if 'add' in this and 'new' in this: if 'add' not in this

Question 29

How do you unindent an entire length of code

Answer 29

Copy everything Shift + Tab

Question 30

Take everything after 'add' and print it: variable = 'add clean the bag'

Answer 30

Starts at the 4th spot 'c; print(variable[4:]) If we put 9 at the end, it would mean end at the space before the 9

Question 31

What's the difference between 'if' and 'elif'?

Answer 31

All ifs will be checked Elifs are only checked if ifs aren't true

Question 32

How do I tell if the string is a number or contains a number

Answer 32

This checks if the entire string is a digit Has to be a string hello = "5" hell.isdigit() ========== Check if something CONTAINS a number digit = False for i in password: if i.isdigit() digit = True

Question 33

Check if the below variable is uppercase variable = HELLO

Answer 33

print(variable.isupper())

Question 34

The variable true contains the following booleans: true = [True, True, True] How do we check if they're all true?

Answer 34

if all(true): print('all true') better than if all(true) == True

Question 35

Show via boolean if the variable var contains "add" at the beginning of it

Answer 35

var.startswith("add")

Question 36

You are receiving an error called ValueError in your code, create a good response for it

Answer 36

try: something except ValueError: print("Your command is not valid") continue finally: Continue will take you to the beginning of the loop Break will break you out of the loop

Question 37

What are the two types of errors you can receive?

Answer 37

Syntax and Exception Syntax - you typed something incorrectly Exception - Logical error. Something it not working using the tools you used.

Question 38

Break the program interaction and close it out with the message "an error occurred."

Answer 38

exit("An error occurred)

Question 39

Specify to the function to return absolutely nothing

Answer 39

def greet(): return None

Question 40

Add together all the elements in a list show the biggest number in a list show the lowest number in a list

Answer 40

sum(list) max(list) min(list)

Question 41

what is "var" in: def this(var):

Answer 41

var is a parameter when it is referenced outside of it is an argument, what value you give the argument is the argument value.

Question 42

Separate a variable into two different elements of a list

Answer 42

var = "4 12" list = var.split(" ")

Question 43

What is decoupling and how would you perform it below? def convert(): feet = 3 sentence = f"there are {feet} feet" return sentence

Answer 43

Delete the sentence and only return the data which is needed. In this case it would be "feet".

Question 44

Write a docstring for your function What does this do?

Answer 44

Writes a description for the function def function(): """ Return a string blah blah blah""" print(help(function))

Question 45

Decouple a variable from a function

Answer 45

Decoupling just means you've formatted your function to do something simple and you're not giving back the info super structured. For instance, instead of returning the info in a sentence, just give it back in terms of the hard data

Question 46

What happens when you return more than one object from a function? make it return as a dictionary access it

Answer 46

def parse(): return feet, inches it's given back in the form of a tuple return {"feet": feet, "inches": inches} print(parse()["feet"])

Question 47

How would you create your own python module? Why would you do this? How would you import a module stored in a directory in the same folder as your project?

Answer 47

Move functions over to a separate python document in the same directory. You do this so the code doesn't get too long and complicated. This is really good for organization. from functions import get_todos, write_todos or import functions functions.get_todos() functions.write_todos() IF MODULES WAS THE NAME OF THE DIRECTORY AND FUNCTIONS WAS THE NAME OF THE FILE: from modules import functions

Question 48

What would happen if you added the line print("statement") to a module and imported it What would we do if we only wanted it to print if that module was ran a the main program Why does this work?

Answer 48

It would print put an if statement at the end: if __name__ == "__main__" print("hello") if you print(__name__) it will say __main__

Question 49

What is version control What is github

Answer 49

Lets you track changes between versions download one: git subversion (apache) Bazaar mercurial Cloud based storage for code if you lose access to your code Used for sharing collaboration

Question 50

Use time to show the date and time Is this a standard or local module? Look at time's info

Answer 50

import time time.strftime("%b %d, %Y %H:%M:%S") python.org will have info about this method This is a standard module, it is built into python for you to use. A local module would be in the same directory, something we essentially made. dir(time) you'll find things like CLOCK_MONOTONIC, this and others like it are just variables.

Question 51

Use the glob module Use the csv module

Answer 51

import glob myfiles = glob.glob("files/*.txt") print(myfiles) This will show all text files in list format. You could use this to open multiple files. ======= Create a file that ends with .csv - weather.csv "Station","Temperature" "Kuala Lumpur","45" "New York","25" New python file import csv with open("weather.csv", "r") as file: data = list(csv.reader(file)) date <- this is an iterator object instance now, it's not readable, convert it to a list type outside of with: print(data) This will give you a list of lists, row by row NOW LET'S USE IT city = input("Enter a city: ") for row in data: if row[0] == city: print(row[1]) WE'VE JUST PRINTED OUT THE TEMP FOR NEW YORK

Question 52

Use the shutil module

Answer 52

copy files, create zip files, extract files from zip files shell utility = shutil import shutil shutil.make_archive("output", "zip", "files") This will take the name of the archive we want OUTPUT, we want it compressed ZIP and then the directory that contains all the file we want compressed FILES

Question 53

Use the webbrowser module

Answer 53

import webrowser user_term = input("Enter a search term: ").replace(" ","+") webbrowser.open("https://google.com/search?q=" + user_term)

Question 54

If you were to create a json file that contained questions, options, and answers for a quiz, how would you format it?

Answer 54

[{"question1":"actual question", "options":"all options", "answer":"actual answer" }, {"question2":"actual question", "options":"all options", "answer":"actual answer" } ]

Question 55

You have a json file in your app folder. Import json, open the file, load it's content Print out the first question of the quiz you made in the json file.

Answer 55

import json with open("questions.json", "r") as file: content = file.read() data = json.loads(content) for question in data: print(question["question_text"] for index, alternative in enumerate(question["alternatives"]): print(index, "-", alternative) QUESTION HERE WILL FUNCTION AS THE FIRST ELEMENT OF THE LIST, WHICH IS THE FIRST DICTIONARY. CALLING "QUESTION_TEXT" CALLS FOR THE KEY'S VALUE, WHICH IS THE QUESTION.

Question 56

you have the following dictionary: x = {"a": 6} How would you add the key "b" and give it a value of 7?

Answer 56

x["u"] = 2