# lecture 5, 10.10.2024, string manipulation / exception handling
print("Welcome!")

# NEW FILE

# " and ' do the same thing => define a string
# we can mix " and ' if we first start with " and then '
# also vice versa
name = 'John "Supercoder" Doe'
print(name)

# also possible
name = "John 'Supercoder' Doe"
print(name)

# we can also literally use quotation marks
# with the \-character => special character
name = "John \"Supercoder\" Doe"
print(name)

# virtually both are the same value-wise
name2 = "John"
name3 = 'John'

print(name2)
print(name3)

# NEW FILE

# you could also ask this from the user
text = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

# from first to 10th
# REMEMBER: empty space is also a letter/character
# this is very useful in the text shortening exercises in exercises 4
subtext1 = text[0:10]
print(subtext1)

# take from the middle, starting at position 10
# until 15 (11th character onwards)
subtext2 = text[10:15]
print(subtext2)

# start from 6th character, and after that
# take all characters that remain
# (take everything after this character
subtext3 = text[5:]
print(subtext3)

# get last five characters by using the negative index
# so basically start from the 5th character from the end, and take
# all text that is left
subtext4 = text[-5:]
print(subtext4)

# sometimes handy, just remove the final character (often some
# kind of extra mess we have to clean up
subtext5 = text[0:-1]
print(subtext5)

# NEW FILE

text = input("Write a sentence:\n")

text_length = len(text)

# get text length / amount of characters
# empty spaces are also characters
print(f"Text length: {text_length} characters")

# check if text is long or short
# this could also be useful in checking
# that is the user's new password long enough
if text_length > 30:
    print("Long text!")

    # text is too long, let's shorten it up and add the
    # typical ... in the end
    shortened = text[0:30] + "..."
    print(shortened)
else:
    print("Short text...")

# count the amount of letters, this case lowercase a
# NOTE: capital letters and lowercase letters are completely
# different letters in programming, because otherwise
# the code would never know went to print a capital or
# or a lowercase letter
a_letters = text.count("a")
print(f"Amount of a-characters: {a_letters}")

# check if text is empty
if text_length == 0:
    print("EMPTY TEXT GIVEN!")
else:
    print("Text not empty.")

# NEW FILE

text = input("Give text:\n")

# reversing a text in Python is quite different
# than in other languages, but this works
# basically this uses the substring -syntax
# but we choose everything from beginning to end, but traverse
# the string the other way (-1)
# [ : : -1]

# palindrome is a word that is the same forwards and backwards
# for example "racecar" is the same both directions
reversed_text = text[::-1]
print(reversed_text)

# NEW FILE

# our test data
drinks = "water, milk, coffee, tea, water"

# replace water with
drinks = drinks.replace("water", "soda")
print(drinks)
print()

# any character will do, even special characters like new line!
new_drinks = drinks.replace(", ", "\n")
print(new_drinks)

# NEW FILE

# our test data
drinks = "water, milk, coffee, tea, water"

# replace water with
# if you want to limit the amount of replacements
# try: drinks.replace("water", "soda", 2)
drinks = drinks.replace("water", "soda")
print(drinks)
print()

# any character will do, even special characters like new line!
# you can "remove" a word by replacing with an empty string ""
new_drinks = drinks.replace(", ", "\n")
print(new_drinks)
print()

# ask user for text
usertext = input("What would you like to drink?\n")

# check if the user's text was in the original text
if usertext in drinks:
    print("Drink found!")
else:
    print("We don't have that, sorry!")

# NEW FILE

text = input("Give a value:\n")

# use this as the basis for advanced exercise 4-7
# e.g. 12345 => number, "one two three four five" -> text
if text.isnumeric():
    print("User gave numbers...")
else:
    print("User gave text!")

# NEW FILE

text = input("Are you a student or an adult? (s/a)\n")

# a nice trick you can do with string functions
# we force the value to lowercase
# and now we don't have to have complex comparisons
# like if text == "s" or text == "S"
text = text.lower()

# check the user's status (given by input)
if text == "s":
    print("You're a student!")
elif text == "a":
    print("You're an adult!")
else:
    print("Incorrect selection")

# NEW FILE

# try-block has the code that has the potential
# to crash in some event. in this case, our code assumes
# user always gives a number, but what if they give text?
# except -block is launched, if the error actually happens
# print error message etc.
try:
    number = input("Give a number:\n")
    number = int(number)
    print(f"Your number: {number}")
except ValueError:
    print("You wrote text, only numbers supported. Run app again!")

# NEW FILE
# this version handles two different types of errors
# remember: all uncaught errors will crash the app!
try:
    number = input("Give a number:\n")
    number = int(number)
    result = 100 / number
    print(f"Result: {result}")
except ValueError:
    print("You wrote text, only numbers supported. Run app again!")
except ZeroDivisionError:
    print("Can't divide by zero, run app again!")

# NEW FILE

# you can also create a generic error handling
# but the messages are often technical and straigt from Python
# might also be a good idea to wrap to whole
# basic app around this, so it doesn't crash in most cases
try:
    number = input("Give a number:\n")
    number = int(number)
    result = 100 / number
    print(f"Result: {result}")
except Exception as e:
    print(f"Error message: {e}")

# NEW FILE

# this example combines everything: conditional statements,
# string operations and error management

# INSTRUCTIONS: create an application, that checks if the given
# client identifier is in correct format (imagine: phone operators etc.)
# example client identifier = C1234_2345

# logic: client identifier is ALWAYS 10 characters long, sixth letter is always
# underscore,

# let's use try/except just in case
# C1234_2345

try:
    # ask user for a client identifier
    client = input("Give a client identifier:\n")

    text_length = len(client)

    # check that the length is exactly 10
    if text_length != 10:
        print("Client identifier, incorrect length (10 required).")
    elif client[5] != "_":
        # sixth character has to be underscore
        print("Underscore missing in client identifier.")
    else:
        # split the identifier into client and order number
        identifier = client[0:5]
        order = client[6:10]

        # convert order number to in
        order = int(order)

        print(identifier)
        print(order)

        # if the conditions above were OK, we will finally arrive
        # this else-statement
        print("Identifier OK!")

except Exception as e:
    # if something goes wrong, do this lastly
    # for example: C1234_HOLA
    print("Incorrect client identifier.")