# ---------- FORCE USER TO ENTER A NUMBER ----------

# By giving the while a value of True it will cycle until a break is reached

while True:

# If we expect an error can occur surround potential error with try

try:

number = int(input("Please enter a number : "))

break

# The code in the except block provides an error message to set things right

# We can either target a specific error like ValueError

except ValueError:

print("You didn't enter a number")

# We can target all other errors with a default

except:

print("An unknown error occurred")

print("Thank you for entering a number")

# ---------- Problem : Implement a Do While Loop ----------

# Now I want you to implement a Do While loop in Python

# They always execute all of the code at least once and at

# the end check if a condition is true that would warrant

# running the code again. They have this format

# do {

# ... Bunch of code ...

# } while(condition)

# I'll create a guessing game in which the user must chose

# a number between 1 and 10 of the following format

'''

Guess a number between 1 and 10 : 1

Guess a number between 1 and 10 : 3

Guess a number between 1 and 10 : 5

Guess a number between 1 and 10 : 7

You guessed it

'''

# Hint : You'll need a while and break

secret_number = 7

while True:

guess = int(input("Guess a number between 1 and 10 : "))

if guess == secret_number:

print("You guessed it")

break

# ---------- MATH MODULE ----------

# Python provides many functions with its Math module

import math

# Because you used import you access methods by referencing the module

print("ceil(4.4) = ", math.ceil(4.4))

print("floor(4.4) = ", math.floor(4.4))

print("fabs(-4.4) = ", math.fabs(-4.4))

# Factorial = 1 * 2 * 3 * 4

print("factorial(4) = ", math.factorial(4))

# Return remainder of division

print("fmod(5,4) = ", math.fmod(5,4))

# Receive a float and return an int

print("trunc(4.2) = ", math.trunc(4.2))

# Return x^y

print("pow(2,2) = ", math.pow(2,2))

# Return the square root

print("sqrt(4) = ", math.sqrt(4))

# Special values

print("math.e = ", math.e)

print("math.pi = ", math.pi)

# Return e^x

print("exp(4) = ", math.factorial(4))

# Return the natural logarithm e * e * e ~= 20 so log(20) tells

# you that e^3 ~= 20

print("log(20) = ", math.log(20))

# You can define the base and 10^3 = 1000

print("log(1000,10) = ", math.log(1000,10))

# You can also use base 10 like this

print("log10(1000) = ", math.log10(1000))

# We have the following trig functions

# sin, cos, tan, asin, acos, atan, atan2, asinh, acosh,

# atanh, sinh, cosh, tanh

# Convert radians to degrees and vice versa

print("degrees(1.5708) = ", math.degrees(1.5708))

print("radians(90) = ", math.radians(90))

# ---------- ACCURATE FLOATING POINT CALCULATIONS ----------

# The decimal module provides for more accurate floating point calculations

# With from you can reference methods without the need to reference the module

# like we had to do with math above

# We create an alias being D here to avoid conflicts with methods with

# the same name

from decimal import Decimal as D

sum = D(0)

sum += D("0.01")

sum += D("0.01")

sum += D("0.01")

sum -= D("0.03")

print("Sum = ", sum)

# ---------- STRINGS ----------

# Text is stored using the string data type

# You can use type to see the data type of a value

print(type(3))

print(type(3.14))

# Single quotes or double are both used for strings

print(type("3"))

print(type('3'))

samp_string = "This is a very important string"

# Each character is stored in a series of boxes labeled with index numbers

# You can get a character by referencing an index

print(samp_string[0])

# Get the last character

print(samp_string[-1])

# Get the last character

print(samp_string[3+5])

# Get the string length

print("Length :", len(samp_string))

# Get a slice by saying where to start and end

# The 4th index isn't returned

print(samp_string[0:4])

# Get everything starting at an index

print(samp_string[8:])

# Join or concatenate strings with +

print("Green " + "Eggs")

# Repeat strings with *

print("Hello " * 5)

# Convert an int into a string

num_string = str(4)

# Cycle through each character with for

for char in samp_string:

print(char)

# Cycle through characters in pairs

# Subtract 1 from the length because length is 1 more then the highest index

# because strings are 0 indexed

# Use range starting at index 0 through string length and increment by

# 2 each time through

for i in range(0, len(samp_string)-1, 2):

print(samp_string[i] + samp_string[i+1])

# Computers assign characters with a number known as a Unicode

# A-Z have the numbers 65-90 and a-z 97-122

# You can get the Unicode code with ord()

print("A =", ord("A"))

# You can convert from Unicode with chr

print("65 =", chr(65))

# ---------- PROBLEM : SECRET STRING ----------

# Receive a uppercase string and then hide its meaning by turning

# it into a string of unicodes

# Then translate it from unicode back into its original meaning

norm_string = input("Enter a string to hide in uppercase: ")

secret_string = ""

# Cycle through each character in the string

for char in norm_string:

# Store each character code in a new string

secret_string += str(ord(char))

print("Secret Message :", secret_string)

norm_string = ""

# Cycle through each character code 2 at a time by incrementing by

# 2 each time through since unicodes go from 65 to 90

for i in range(0, len(secret_string)-1, 2):

# Get the 1st and 2nd for the 2 digit number

char_code = secret_string[i] + secret_string[i+1]

# Convert the codes into characters and add them to the new string

norm_string += chr(int(char_code))

print("Original Message :", norm_string)

# ---------- SUPER AWESOME MIND SCRAMBLING PROBLEM ----------

# Make the above work with upper and lowercase with 1 addition and

# 1 subtraction

# Add these 2 changes

# secret_string += str(ord(char) - 23)

# norm_string += chr(int(char_code) + 23)