Lecture 6 bis : Additional exercices (basics of python)

December, 2021 - François HU

Master of Science - EPITA

This lecture is available here: https://curiousml.github.io/

Exercices

These exercices are considered "easy" exercices.

Exercice 1: functions - easy

Create a function add_more, that produces the following results:

>>> add_more(1, 1)
3
>>> add_more(1, -1)
1
>>> add_more(5, 0)
6

def add_more(a, b):
    return(a+b+1)

print(add_more(1, 1))
print(add_more(1, -1))
print(add_more(5, 0))

3
1
6

Exercice 2: lists - easy

Crate a function create_list, that produces the following results:

>>> create_list(5)
[1, 4, 9, 16, 25]
>>> create_list(10)
[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
>>> create_list(-1)
[]

def create_list(a):
    return [i**2 for i in range(1,a+1)]

print(create_list(5))
print(create_list(10))
print(create_list(-1))

[1, 4, 9, 16, 25]
[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
[]

Exercice 3: lists - easy

Create a function add_lists that produces the following results (we assume that the two lists have same length)

>>> add_lists([1, 2, 3], [-1, 2, -2])
[0, 4, 1]
>>> add_lists([1, 0, 0], [-1, 2, -2])
[0, 2, -2]
>>> add_lists([1, 0, 0], [0, 1, 1])
[1, 1, 1]

def add_lists(l1, l2):
    l = []
    for i in range(len(l1)):
        l.append(l1[i]+l2[i])
    return l

print(add_lists([1, 2, 3], [-1, 2, -2]))
print(add_lists([1, 0, 0], [-1, 2, -2]))
print(add_lists([1, 0, 0], [0, 1, 1]))

[0, 4, 1]
[0, 2, -2]
[1, 1, 1]

Exercice 4: lists - normal

Create a function add_lists_improved that produces the following results (we don't assume that the two lists have same length)

>>> add_lists_improved([1, 2, 3], [-1, 2, -2])
[0, 4, 1]
>>> add_lists_improved([1, 2, 3], [-1, 2, -2, 1, 2])
[0, 4, 1, 1, 2]
>>> add_lists_improved([1, 0, 0, -1, 0], [0, 1, 1])
[1, 1, 1, -1, 0]

def add_lists_improved(l1, l2):
    l = []
    for i in range(max(len(l1), len(l2))):
        if i>=len(l1):
            l.append(l2[i])
        elif i>=len(l2):
            l.append(l1[i])
        else:
            l.append(l1[i]+l2[i])
    return l

print(add_lists_improved([1, 2, 3], [-1, 2, -2]))
print(add_lists_improved([1, 2, 3], [-1, 2, -2, 1, 2]))
print(add_lists_improved([1, 0, 0, -1, 0], [0, 1, 1]))

[0, 4, 1]
[0, 4, 1, 1, 2]
[1, 1, 1, -1, 0]

Exercice 5: dictionaries - easy

We have the following dictionary students (don't forget to execute the cell):

# DON'T MODIFY THIS PROGRAM, JUST EXECUTE IT
students = {'Name': ['Arthur',
                     'Marcial',
                     'Margaux',
                     'François',
                     'Julie',
                     'Sophie',
                     'Alex',
                     'Christine'
                    ],
            'Grade': [8, 2, 15, 3, 7, 10, 11, 16]}

• In the field Name of the dictionary, add (e.g. use append command) a new name "Sacha".

• In the field Grade of the dictionary, add (e.g. use append command) a new grade 19.

students["Name"].append("Sacha")
students["Grade"].append(19)
students

{'Name': ['Arthur',
  'Marcial',
  'Margaux',
  'François',
  'Julie',
  'Sophie',
  'Alex',
  'Christine',
  'Sacha'],
 'Grade': [8, 2, 15, 3, 7, 10, 11, 16, 19]}

Exercice 6: dictionaries - normal

Let us continue working with the previous dictionary students.

• Add a new field Upgrade in the dictionary. The associated value is the lists students["Grade"] where each value is incremented by 1.

students["Upgrade"] = [g+1 for g in students["Grade"]]
students

{'Name': ['Arthur',
  'Marcial',
  'Margaux',
  'François',
  'Julie',
  'Sophie',
  'Alex',
  'Christine',
  'Sacha'],
 'Grade': [8, 2, 15, 3, 7, 10, 11, 16, 19],
 'Upgrade': [9, 3, 16, 4, 8, 11, 12, 17, 20]}

Exercice 7: strings - easy

Create a function concatenate_str that produces the following results:

>>> concatenate_str("I", "am")
I am
>>> concatenate_str("a", "student")
a student
>>> concatenate_str("of", "EPITA")
of EPITA

def concatenate_str(s1, s2):
    return s1 + " " + s2

print(concatenate_str("I", "am"))
print(concatenate_str("a", "student"))
print(concatenate_str("of", "EPITA"))

I am
a student
of EPITA