0x04-python-more_data_structures

0x04. Python - More Data Structures: Set, Dictionary

By Guillaume\

Resources

Read or watch:

Data structures\
Lambda, filter, reduce and map\
Learn to Program 12 Lambda Map Filter Reduce

man or help:

python3

Learning Objectives

At the end of this project, you are expected to be able to explain to anyone, without the help of Google:
General

Why Python programming is awesome\
What are sets and how to use them\
What are the most common methods of set and how to use them\
When to use sets versus lists\
How to iterate into a set\
What are dictionaries and how to use them\
When to use dictionaries versus lists or sets\
What is a key in a dictionary\
How to iterate over a dictionary\
What is a lambda function\
What are the map, reduce and filter functions

Requirements
General

Allowed editors: vi, vim, emacs\
All your files will be interpreted/compiled on Ubuntu 20.04 LTS using python3 (version 3.8.5)\
All your files should end with a new line\
The first line of all your files should be exactly #!/usr/bin/python3\
A README.md file, at the root of the folder of the project, is mandatory\
Your code should use the pycodestyle (version 2.7.*)\
All your files must be executable\
The length of your files will be tested using wc

Tasks
0. Squared simple
mandatory

Write a function that computes the square value of all integers of a matrix.

Prototype: def square_matrix_simple(matrix=[]):\
matrix is a 2 dimensional array\
Returns a new matrix:\
    Same size as matrix\
    Each value should be the square of the value of the input\
Initial matrix should not be modified\
You are not allowed to import any module\
You are allowed to use regular loops, map, etc.

guillaume@ubuntu:~/0x04$ cat 0-main.py
#!/usr/bin/python3
square_matrix_simple = import('0-square_matrix_simple').square_matrix_simple

matrix = [
[1, 2, 3],
[4, 5, 6],
[7, 8, 9]
]

new_matrix = square_matrix_simple(matrix)
print(new_matrix)
print(matrix)

guillaume@ubuntu:/0x04$ ./0-main.py
[[1, 4, 9], [16, 25, 36], [49, 64, 81]]
[[1, 2, 3], [4, 5, 6], [7, 8, 9]]
guillaume@ubuntu:/0x04$

Repo:

GitHub repository: alx-higher_level_programming\
Directory: 0x04-python-more_data_structures\
File: 0-square_matrix_simple.py

1. Search and replace
mandatory

Write a function that replaces all occurrences of an element by another in a new list.

Prototype: def search_replace(my_list, search, replace):\
my_list is the initial list\
search is the element to replace in the list\
replace is the new element\
You are not allowed to import any module

guillaume@ubuntu:~/0x04$ cat 1-main.py
#!/usr/bin/python3
search_replace = import('1-search_replace').search_replace

my_list = [1, 2, 3, 4, 5, 4, 2, 1, 1, 4, 89]
new_list = search_replace(my_list, 2, 89)

print(new_list)
print(my_list)

guillaume@ubuntu:/0x04$ ./1-main.py
[1, 89, 3, 4, 5, 4, 89, 1, 1, 4, 89]
[1, 2, 3, 4, 5, 4, 2, 1, 1, 4, 89]
guillaume@ubuntu:/0x04$

Repo:

GitHub repository: alx-higher_level_programming\
Directory: 0x04-python-more_data_structures\
File: 1-search_replace.py

2. Unique addition
mandatory

Write a function that adds all unique integers in a list (only once for each integer).

Prototype: def uniq_add(my_list=[]):\
You are not allowed to import any module

guillaume@ubuntu:~/0x04$ cat 2-main.py
#!/usr/bin/python3
uniq_add = import('2-uniq_add').uniq_add

my_list = [1, 2, 3, 1, 4, 2, 5]
result = uniq_add(my_list)
print("Result: {:d}".format(result))

guillaume@ubuntu:/0x04$ ./2-main.py
Result: 15
guillaume@ubuntu:/0x04$

Repo:

GitHub repository: alx-higher_level_programming\
Directory: 0x04-python-more_data_structures\
File: 2-uniq_add.py

3. Present in both
mandatory

Write a function that returns a set of common elements in two sets.

Prototype: def common_elements(set_1, set_2):\
You are not allowed to import any module

guillaume@ubuntu:~/0x04$ cat 3-main.py
#!/usr/bin/python3
common_elements = import('3-common_elements').common_elements

set_1 = { "Python", "C", "Javascript" }
set_2 = { "Bash", "C", "Ruby", "Perl" }
c_set = common_elements(set_1, set_2)
print(sorted(list(c_set)))

guillaume@ubuntu:/0x04$ ./3-main.py
['C']
guillaume@ubuntu:/0x04$

Repo:

GitHub repository: alx-higher_level_programming\
Directory: 0x04-python-more_data_structures\
File: 3-common_elements.py

4. Only differents
mandatory

Write a function that returns a set of all elements present in only one set.

Prototype: def only_diff_elements(set_1, set_2):\
You are not allowed to import any module

guillaume@ubuntu:~/0x04$ cat 4-main.py
#!/usr/bin/python3
only_diff_elements = import('4-only_diff_elements').only_diff_elements

set_1 = { "Python", "C", "Javascript" }
set_2 = { "Bash", "C", "Ruby", "Perl" }
od_set = only_diff_elements(set_1, set_2)
print(sorted(list(od_set)))

guillaume@ubuntu:/0x04$ ./4-main.py
['Bash', 'Javascript', 'Perl', 'Python', 'Ruby']
guillaume@ubuntu:/0x04$

Repo:

GitHub repository: alx-higher_level_programming\
Directory: 0x04-python-more_data_structures\
File: 4-only_diff_elements.py

5. Number of keys
mandatory

Write a function that returns the number of keys in a dictionary.

Prototype: def number_keys(a_dictionary):\
You are not allowed to import any module

guillaume@ubuntu:~/0x04$ cat 5-main.py
#!/usr/bin/python3
number_keys = import('5-number_keys').number_keys

a_dictionary = { 'language': "C", 'number': 13, 'track': "Low level" }
nb_keys = number_keys(a_dictionary)
print("Number of keys: {:d}".format(nb_keys))

guillaume@ubuntu:/0x04$ ./5-main.py
Number of keys: 3
guillaume@ubuntu:/0x04$

Repo:

GitHub repository: alx-higher_level_programming\
Directory: 0x04-python-more_data_structures\
File: 5-number_keys.py

6. Print sorted dictionary
mandatory

Write a function that prints a dictionary by ordered keys.

Prototype: def print_sorted_dictionary(a_dictionary):\
You can assume that all keys are strings\
Keys should be sorted by alphabetic order\
Only sort keys of the first level (don't sort keys of a dictionary inside the main dictionary)\
Dictionary values can have any type\
You are not allowed to import any module

guillaume@ubuntu:~/0x04$ cat 6-main.py
#!/usr/bin/python3
print_sorted_dictionary = import('6-print_sorted_dictionary').print_sorted_dictionary

a_dictionary = { 'language': "C", 'Number': 89, 'track': "Low level", 'ids': [1, 2, 3] }
print_sorted_dictionary(a_dictionary)

guillaume@ubuntu:/0x04$ ./6-main.py
Number: 89
ids: [1, 2, 3]
language: C
track: Low level
guillaume@ubuntu:/0x04$

Repo:

GitHub repository: alx-higher_level_programming\
Directory: 0x04-python-more_data_structures\
File: 6-print_sorted_dictionary.py

7. Update dictionary
mandatory

Write a function that replaces or adds key/value in a dictionary.

Prototype: def update_dictionary(a_dictionary, key, value):\
key argument will be always a string\
value argument will be any type\
If a key exists in the dictionary, the value will be replaced\
If a key doesn't exist in the dictionary, it will be created\
You are not allowed to import any module

guillaume@ubuntu:~/0x04$ cat 7-main.py
#!/usr/bin/python3
update_dictionary = import('7-update_dictionary').update_dictionary
print_sorted_dictionary = import('6-print_sorted_dictionary').print_sorted_dictionary

a_dictionary = { 'language': "C", 'number': 89, 'track': "Low level" }
new_dict = update_dictionary(a_dictionary, 'language', "Python")
print_sorted_dictionary(new_dict)
print("--")
print_sorted_dictionary(a_dictionary)

print("--")
print("--")

new_dict = update_dictionary(a_dictionary, 'city', "San Francisco")
print_sorted_dictionary(new_dict)
print("--")
print_sorted_dictionary(a_dictionary)

guillaume@ubuntu:/0x04$ ./7-main.py
language: Python
number: 89
track: Low level
--
language: Python
number: 89
track: Low level
--
--
city: San Francisco
language: Python
number: 89
track: Low level
--
city: San Francisco
language: Python
number: 89
track: Low level
guillaume@ubuntu:/0x04$

Repo:

GitHub repository: alx-higher_level_programming\
Directory: 0x04-python-more_data_structures\
File: 7-update_dictionary.py

8. Simple delete by key
mandatory

Write a function that deletes a key in a dictionary.

Prototype: def simple_delete(a_dictionary, key=""):\
key argument will be always a string\
If a key doesn't exist, the dictionary won't change\
You are not allowed to import any module

guillaume@ubuntu:~/0x04$ cat 8-main.py
#!/usr/bin/python3
simple_delete = import('8-simple_delete').simple_delete
print_sorted_dictionary = \ import('6-print_sorted_dictionary').print_sorted_dictionary

a_dictionary = { 'language': "C", 'Number': 89, 'track': "Low", 'ids': [1, 2, 3] }
new_dict = simple_delete(a_dictionary, 'track')
print_sorted_dictionary(a_dictionary)
print("--")
print_sorted_dictionary(new_dict)

print("--")
print("--")
new_dict = simple_delete(a_dictionary, 'c_is_fun')
print_sorted_dictionary(a_dictionary)
print("--")
print_sorted_dictionary(new_dict)

guillaume@ubuntu:/0x04$ ./8-main.py
Number: 89
ids: [1, 2, 3]
language: C
--
Number: 89
ids: [1, 2, 3]
language: C
--
--
Number: 89
ids: [1, 2, 3]
language: C
--
Number: 89
ids: [1, 2, 3]
language: C
guillaume@ubuntu:/0x04$

Repo:

GitHub repository: alx-higher_level_programming\
Directory: 0x04-python-more_data_structures\
File: 8-simple_delete.py

9. Multiply by 2
mandatory

Write a function that returns a new dictionary with all values multiplied by 2

Prototype: def multiply_by_2(a_dictionary):\
You can assume that all values are only integers\
Returns a new dictionary\
You are not allowed to import any module

guillaume@ubuntu:~/0x04$ cat 9-main.py
#!/usr/bin/python3
multiply_by_2 = import('9-multiply_by_2').multiply_by_2
print_sorted_dictionary = \ import('6-print_sorted_dictionary').print_sorted_dictionary

a_dictionary = {'John': 12, 'Alex': 8, 'Bob': 14, 'Mike': 14, 'Molly': 16}
new_dict = multiply_by_2(a_dictionary)
print_sorted_dictionary(a_dictionary)
print("--")
print_sorted_dictionary(new_dict)

guillaume@ubuntu:/0x04$ ./9-main.py
Alex: 8
Bob: 14
John: 12
Mike: 14
Molly: 16
--
Alex: 16
Bob: 28
John: 24
Mike: 28
Molly: 32
guillaume@ubuntu:/0x04$

Repo:

GitHub repository: alx-higher_level_programming\
Directory: 0x04-python-more_data_structures\
File: 9-multiply_by_2.py

10. Best score
mandatory

Write a function that returns a key with the biggest integer value.

Prototype: def best_score(a_dictionary):\
You can assume that all values are only integers\
If no score found, return None\
You can assume all students have a different score\
You are not allowed to import any module

guillaume@ubuntu:~/0x04$ cat 10-main.py
#!/usr/bin/python3
best_score = import('10-best_score').best_score

a_dictionary = {'John': 12, 'Bob': 14, 'Mike': 14, 'Molly': 16, 'Adam': 10}
best_key = best_score(a_dictionary)
print("Best score: {}".format(best_key))

best_key = best_score(None)
print("Best score: {}".format(best_key))

guillaume@ubuntu:/0x04$ ./10-main.py
Best score: Molly
Best score: None
guillaume@ubuntu:/0x04$

Repo:

GitHub repository: alx-higher_level_programming\
Directory: 0x04-python-more_data_structures\
File: 10-best_score.py

11. Multiply by using map
mandatory

Write a function that returns a list with all values multiplied by a number without using any loops.

Prototype: def multiply_list_map(my_list=[], number=0):\
Returns a new list:\
    Same length as my_list\
    Each value should be multiplied by number\
Initial list should not be modified\
You are not allowed to import any module\
You have to use map\
Your file should be max 3 lines

guillaume@ubuntu:~/0x04$ cat 11-main.py
#!/usr/bin/python3
multiply_list_map = import('11-multiply_list_map').multiply_list_map

my_list = [1, 2, 3, 4, 6]
new_list = multiply_list_map(my_list, 4)
print(new_list)
print(my_list)

guillaume@ubuntu:/0x04$ ./11-main.py
[4, 8, 12, 16, 24]
[1, 2, 3, 4, 6]
guillaume@ubuntu:/0x04$

Repo:

GitHub repository: alx-higher_level_programming\
Directory: 0x04-python-more_data_structures\
File: 11-multiply_list_map.py

12. Roman to Integer
mandatory

Technical interview preparation:

You are not allowed to google anything\
Whiteboard first

Create a function def roman_to_int(roman_string): that converts a Roman numeral to an integer.

You can assume the number will be between 1 to 3999.\
def roman_to_int(roman_string) must return an integer\
If the roman_string is not a string or None, return 0

guillaume@ubuntu:~/0x04$ cat 12-main.py
#!/usr/bin/python3
""" Roman to Integer test file
"""
roman_to_int = import('12-roman_to_int').roman_to_int

roman_number = "X"
print("{} = {}".format(roman_number, roman_to_int(roman_number)))

roman_number = "VII"
print("{} = {}".format(roman_number, roman_to_int(roman_number)))

roman_number = "IX"
print("{} = {}".format(roman_number, roman_to_int(roman_number)))

roman_number = "LXXXVII"
print("{} = {}".format(roman_number, roman_to_int(roman_number)))

roman_number = "DCCVII"
print("{} = {}".format(roman_number, roman_to_int(roman_number)))

guillaume@ubuntu:/0x04$ ./12-main.py
X = 10
VII = 7
IX = 9
LXXXVII = 87
DCCVII = 707
guillaume@ubuntu:/0x04$

Repo:

GitHub repository: alx-higher_level_programming\
Directory: 0x04-python-more_data_structures\
File: 12-roman_to_int.py

13. Weighted average!

#advanced

Score: 0.00% (Checks completed: 0.00%)

Write a function that returns the weighted average of all integers tuple (<score>, <weight>)

• Prototype: def weight_average(my_list=[]):
• Returns 0 if the list is empty
• You are not allowed to import any module

guillaume@ubuntu:~/0x04$ cat 100-main.py
#!/usr/bin/python3
weight_average = __import__('100-weight_average').weight_average

my_list = [(1, 2), (2, 1), (3, 10), (4, 2)]
# = ((1 * 2) + (2 * 1) + (3 * 10) + (4 * 2)) / (2 + 1 + 10 + 2)
result = weight_average(my_list)
print("Average: {:0.2f}".format(result))

guillaume@ubuntu:~/0x04$ ./100-main.py
Average: 2.80
guillaume@ubuntu:~/0x04$

Repo:

• GitHub repository: alx-higher_level_programming
• Directory: 0x04-python-more_data_structures
• File: 100-weight_average.py

14. Squared by using map

#advanced

Score: 0.00% (Checks completed: 0.00%)

Write a function that computes the square value of all integers of a matrix using map

• Prototype: def square_matrix_map(matrix=[]):
• matrix is a 2 dimensional array
• Returns a new matrix:
  • Same size as matrix
  • Each value should be the square of the value of the input
• Initial matrix should not be modified
• You are not allowed to import any module
• You have to use map
• You are not allowed to use for or while
• Your file should be max 3 lines

guillaume@ubuntu:~/0x04$ cat 101-main.py
#!/usr/bin/python3
square_matrix_map =\
    __import__('101-square_matrix_map').square_matrix_map

matrix = [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9]
]

new_matrix = square_matrix_map(matrix)
print(new_matrix)
print(matrix)

guillaume@ubuntu:~/0x04$ ./101-main.py
[[1, 4, 9], [16, 25, 36], [49, 64, 81]]
[[1, 2, 3], [4, 5, 6], [7, 8, 9]]
guillaume@ubuntu:~/0x04$

Repo:

• GitHub repository: alx-higher_level_programming
• Directory: 0x04-python-more_data_structures
• File: 101-square_matrix_map.py

15. Delete by value

#advanced

Score: 0.00% (Checks completed: 0.00%)

Write a function that deletes keys with a specific value in a dictionary.

• Prototype: def complex_delete(a_dictionary, value):
• If the value doesn't exist, the dictionary won't change
• All keys having the searched value have to be deleted
• You are not allowed to import any module

guillaume@ubuntu:~/0x04$ cat 102-main.py
#!/usr/bin/python3
complex_delete = __import__('102-complex_delete').complex_delete
print_sorted_dictionary =\
    __import__('6-print_sorted_dictionary').print_sorted_dictionary

a_dictionary = {'lang': "C", 'track': "Low", 'pref': "C", 'ids': [1, 2, 3]}
new_dict = complex_delete(a_dictionary, 'C')
print_sorted_dictionary(a_dictionary)
print("--")
print_sorted_dictionary(new_dict)

print("--")
print("--")
new_dict = complex_delete(a_dictionary, 'c_is_fun')
print_sorted_dictionary(a_dictionary)
print("--")
print_sorted_dictionary(new_dict)

guillaume@ubuntu:~/0x04$ ./102-main.py
ids: [1, 2, 3]
track: Low
--
ids: [1, 2, 3]
track: Low
--
--
ids: [1, 2, 3]
track: Low
--
ids: [1, 2, 3]
track: Low
guillaume@ubuntu:~/0x04$

Repo:

• GitHub repository: alx-higher_level_programming
• Directory: 0x04-python-more_data_structures
• File: 102-complex_delete.py

16. CPython #1: PyBytesObject

#advanced

Score: 0.00% (Checks completed: 0.00%)

Create two C functions that print some basic info about Python lists and Python bytes objects.

Python lists:

• Prototype: void print_python_list(PyObject *p);
• Format: see example

Python bytes:

• Prototype: void print_python_bytes(PyObject *p);
• Format: see example
• Line "first X bytes": print a maximum of 10 bytes
• If p is not a valid PyBytesObject, print an error message (see example)
• Read /usr/include/python3.4/bytesobject.h

About:

• Python version: 3.4
• Your shared library will be compiled with this command line: gcc -Wall -Werror -Wextra -pedantic -std=c99 -shared -Wl,-soname,libPython.so -o libPython.so -fPIC -I/usr/include/python3.4 103-python.c
• You are not allowed to use the following macros/functions:
  • Py_SIZE
  • Py_TYPE
  • PyList_GetItem
  • PyBytes_AS_STRING
  • PyBytes_GET_SIZE

julien@ubuntu:~/CPython$ python3 --version
Python 3.4.3
julien@ubuntu:~/CPython$ gcc -Wall -Werror -Wextra -pedantic -std=c99 -shared -Wl,-soname,libPython.so -o libPython.so -fPIC -I/usr/include/python3.4 103-python.c
julien@ubuntu:~/CPython$ cat 103-tests.py
import ctypes

lib = ctypes.CDLL('./libPython.so')
lib.print_python_list.argtypes = [ctypes.py_object]
lib.print_python_bytes.argtypes = [ctypes.py_object]
s = b"Hello"
lib.print_python_bytes(s);
b = b'\xff\xf8\x00\x00\x00\x00\x00\x00';
lib.print_python_bytes(b);
b = b'What does the \'b\' character do in front of a string literal?';
lib.print_python_bytes(b);
l = [b'Hello', b'World']
lib.print_python_list(l)
del l[1]
lib.print_python_list(l)
l = l + [4, 5, 6.0, (9, 8), [9, 8, 1024], b"Holberton", "Betty"]
lib.print_python_list(l)
l = []
lib.print_python_list(l)
l.append(0)
lib.print_python_list(l)
l.append(1)
l.append(2)
l.append(3)
l.append(4)
lib.print_python_list(l)
l.pop()
lib.print_python_list(l)
l = ["Holberton"]
lib.print_python_list(l)
lib.print_python_bytes(l);
julien@ubuntu:~/CPython$ python3 103-tests.py
[.] bytes object info
  size: 5
  trying string: Hello
  first 6 bytes: 48 65 6c 6c 6f 00
[.] bytes object info
  size: 8
  trying string: �
  first 9 bytes: ff f8 00 00 00 00 00 00 00
[.] bytes object info
  size: 60
  trying string: What does the 'b' character do in front of a string literal?
  first 10 bytes: 57 68 61 74 20 64 6f 65 73 20
[*] Python list info
[*] Size of the Python List = 2
[*] Allocated = 2
Element 0: bytes
[.] bytes object info
  size: 5
  trying string: Hello
  first 6 bytes: 48 65 6c 6c 6f 00
Element 1: bytes
[.] bytes object info
  size: 5
  trying string: World
  first 6 bytes: 57 6f 72 6c 64 00
[*] Python list info
[*] Size of the Python List = 1
[*] Allocated = 2
Element 0: bytes
[.] bytes object info
  size: 5
  trying string: Hello
  first 6 bytes: 48 65 6c 6c 6f 00
[*] Python list info
[*] Size of the Python List = 8
[*] Allocated = 8
Element 0: bytes
[.] bytes object info
  size: 5
  trying string: Hello
  first 6 bytes: 48 65 6c 6c 6f 00
Element 1: int
Element 2: int
Element 3: float
Element 4: tuple
Element 5: list
Element 6: bytes
[.] bytes object info
  size: 9
  trying string: Holberton
  first 10 bytes: 48 6f 6c 62 65 72 74 6f 6e 00
Element 7: str
[*] Python list info
[*] Size of the Python List = 0
[*] Allocated = 0
[*] Python list info
[*] Size of the Python List = 1
[*] Allocated = 4
Element 0: int
[*] Python list info
[*] Size of the Python List = 5
[*] Allocated = 8
Element 0: int
Element 1: int
Element 2: int
Element 3: int
Element 4: int
[*] Python list info
[*] Size of the Python List = 4
[*] Allocated = 8
Element 0: int
Element 1: int
Element 2: int
Element 3: int
[*] Python list info
[*] Size of the Python List = 1
[*] Allocated = 1
Element 0: str
[.] bytes object info
  [ERROR] Invalid Bytes Object
julien@ubuntu:~/CPython$

Repo:

• GitHub repository: alx-higher_level_programming
• Directory: 0x04-python-more_data_structures
• File: 103-python.c