lists.py

# Day 5 - 30DaysOfPython Challenge
# Lists

# Level 1
# 1 - Declare an empty list
lst = []

# 2 - Declare a list with more than 5 items
lst = [1, 2, 3, 4, 5, 6]

# 3 - Find the length of your list
print(len(lst))

# 4 - Get the first item, the middle item and the last item of the list
print(
    f"First item: {lst[0]}\n"
    f"Last item: {lst[-1]}\n"
    f"Middle item: {lst[len(lst)//2]}"
)

# 5 - Declare a list called mixed_data_types, put your(name, age, height, marital status, address)
mixed_data_types = ["Cobos", 150, 200, "TMI", "Way TMI"]

# 6 - Declare a list variable named it_companies and assign initial values Facebook, Google, Microsoft, Apple, IBM, Oracle and Amazon.
it_companies = ["Facebook", "Google", "Microsoft", "Apple", "IBM", "Oracle", "Amazon"]

# 7 - Print the list using print()
print(it_companies)

# 8 - Print the number of companies in the list
print(len(it_companies))

# 9 - Print the first, middle and last company
print(
    f"First company: {it_companies[0]}\n"
    f"Middle company: {it_companies[len(it_companies)//2]}\n"
    f"Last company: {it_companies[-1]}"
)

# 10 - Print the list after modifying one of the companies
it_companies[0] = "Meta"
print(it_companies)

# 11 - Add an IT company to it_companies
it_companies.append("NVIDIA")
print(it_companies)

# 12 - Insert an IT company in the middle of the companies list
it_companies.insert(len(it_companies)//2, "MiddleCompany")
print(it_companies)

# 13 - Change one of the it_companies names to uppercase (IBM excluded!)
it_companies[0] = it_companies[0].upper() # Lists are modifiable BUT strings are immutable, we need to REASIGN to modify a string inside a list!
print(it_companies)

# 14 - Join the it_companies with a string '#;  '
print(", ".join(it_companies))

# 15 - Check if a certain company exists in the it_companies list.
print("IBM" in it_companies)

# 16 - Sort the list using sort() method
it_companies.sort()
print(it_companies)

# 17 - Reverse the list in descending order using reverse() method
it_companies.reverse()
print(it_companies)

# 18 - Slice out the first 3 companies from the list
print(it_companies[:3]) # Prints only 3 first
print(it_companies[3:]) # Prints all but 3 first

# 19 - Slice out the last 3 companies from the list
print(it_companies[len(it_companies)-3:]) # Prints only 3 last
print(it_companies[:-3]) # Prints all but 3 last

# 20 - Slice out the middle IT company or companies from the list
print(it_companies[len(it_companies)//2]) # Prints middle company
print(it_companies[:len(it_companies)//2] + it_companies[len(it_companies) // 2 + 1:]) # Prints all but middle company

# 21 - Remove the first IT company from the list
it_companies.pop(0)

# 22 - Remove the middle IT company or companies from the list
it_companies.pop(len(it_companies)//2)

# 23 - Remove the last IT company from the list
it_companies.pop()

# 24 - Remove all IT companies from the list
it_companies.clear()

# 25 - Destroy the IT companies list
del it_companies

# 26 - Join the following lists:
front_end = ['HTML', 'CSS', 'JS', 'React', 'Redux']
back_end = ['Node','Express', 'MongoDB']
front_and_back_end = front_end + back_end # Method A
front_end.extend(back_end) # Method B

# 27 - After joining the lists in question 26. Copy the joined list and assign it to a variable full_stack, then insert Python and SQL after Redux.
full_stack = front_and_back_end.copy()
full_stack[full_stack.index("Redux")+1 : full_stack.index("Redux")+1] = ["Python", "SQL"] 
print(full_stack)

# Level 2
# 1 - The following is a list of 10 students ages:
ages = [19, 22, 19, 24, 20, 25, 26, 24, 25, 24]

# Sort the list and find the min and max age
ages.sort()
min_age, max_age = ages[0], ages[-1]

# Add the min age and the max age again to the list
ages.extend([min_age, max_age])

# Find the median age (one middle item or two middle items divided by two)
ages.sort()
if len(ages) % 2 == 0:
    print(f"Even, therefore median = {int((ages[len(ages)//2] + ages[len(ages)//2 - 1])/2)}")
else:
    print(f"Odd, therefore median = {ages[len(ages)//2]}")
    
# Find the average age (sum of all items divided by their number )
avg_age = sum(ages)/len(ages)
print(f"Average age: {avg_age}")

# Find the range of the ages (max minus min)
print(f"Range = {ages[-1] - ages[0]}")

# Compare the value of (min - average) and (max - average), use abs() method
print(abs(min_age - avg_age) == abs(max_age - avg_age))

import sys
sys.path.append("data")
from countries import countries

# Find the middle country(ies) in the countries list
if len(countries) % 2 == 0:
    print(f"Even, therefore 2 middle countries: {countries[len(countries)//2 - 1]}, {countries[len(countries)//2]}")
else:
    print(f"Odd, therefore 1 middle country: {countries[len(countries)//2]}")

# Divide the countries list into two equal lists if it is even if not one more country for the first half.
if len(countries) % 2 == 0:
    print("Even")
    countries1 = countries[:len(countries)//2]
    countries2 = countries[len(countries)//2:]
else:
    print("Odd")
    countries1 = countries[:len(countries)//2 + 1]
    countries2 = countries[len(countries)//2 + 1:]
print(f"n in Countries1: {len(countries1)}\nn in Countries2: {len(countries2)}")

# ['China', 'Russia', 'USA', 'Finland', 'Sweden', 'Norway', 'Denmark']. Unpack the first three countries and the rest as scandic countries.
mini_countries = ['China', 'Russia', 'USA', 'Finland', 'Sweden', 'Norway', 'Denmark']
china, russia, usa, *scandic = mini_countries