Skip to content

Files

Latest commit

samuelselasisamuelselasi
Update README.md
Mar 15, 2023
1ba84d9 · Mar 15, 2023

History

History

0x04-python-more_data_structures

Folders and files

NameName
Last commit message
Last commit date

parent directory

..
__pycache__
__pycache__
Mar 15, 2023
0-main.py
0-main.py
Mar 15, 2023
0-square_matrix_simple.py
0-square_matrix_simple.py
Mar 15, 2023
1-main.py
1-main.py
Mar 15, 2023
1-search_replace.py
1-search_replace.py
Mar 15, 2023
10-best_score.py
10-best_score.py
Mar 15, 2023
10-main.py
10-main.py
Mar 15, 2023
100-main.py
100-main.py
Mar 15, 2023
100-weight_average.py
100-weight_average.py
Mar 15, 2023
101-main.py
101-main.py
Mar 15, 2023
101-square_matrix_map.py
101-square_matrix_map.py
Mar 15, 2023
102-complex_delete.py
102-complex_delete.py
Mar 15, 2023
102-main.py
102-main.py
Mar 15, 2023
103-python.c
103-python.c
Mar 15, 2023
103-tests.py
103-tests.py
Mar 15, 2023
11-main.py
11-main.py
Mar 15, 2023
11-multiply_list_map.py
11-multiply_list_map.py
Mar 15, 2023
12-main.py
12-main.py
Mar 15, 2023
12-roman_to_int.py
12-roman_to_int.py
Mar 15, 2023
2-main.py
2-main.py
Mar 15, 2023
2-uniq_add.py
2-uniq_add.py
Mar 15, 2023
3-common_elements.py
3-common_elements.py
Mar 15, 2023
3-main.py
3-main.py
Mar 15, 2023
4-main.py
4-main.py
Mar 15, 2023
4-only_diff_elements.py
4-only_diff_elements.py
Mar 15, 2023
5-main.py
5-main.py
Mar 15, 2023
5-number_keys.py
5-number_keys.py
Mar 15, 2023
6-main.py
6-main.py
Mar 15, 2023
6-print_sorted_dictionary.py
6-print_sorted_dictionary.py
Mar 15, 2023
7-main.py
7-main.py
Mar 15, 2023
7-update_dictionary.py
7-update_dictionary.py
Mar 15, 2023
8-main.py
8-main.py
Mar 15, 2023
8-simple_delete.py
8-simple_delete.py
Mar 15, 2023
9-main.py
9-main.py
Mar 15, 2023
9-multiply_by_2.py
9-multiply_by_2.py
Mar 15, 2023
README.md
README.md
Mar 15, 2023
libPython.so
libPython.so
Mar 15, 2023

README.md

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

Resources

Read or watch:

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 2.8.*)
  • All your files must be executable
  • The length of your files will be tested using wc

Tasks

0. Squared simple

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$

1. Search and replace

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$

2. Unique addition

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$

3. Present in both

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$

4. Only differents

  • 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$

5. Number of keys

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$

6. Print sorted dictionary

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$

7. Update dictionary

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$

8. Simple delete by key

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$

9. Multiply by 2

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$

10. Best score

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$

11. Multiply by using map

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$

12. Roman to Integer

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$

13. Weighted average!

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$

14. Squared by using map

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$

15. Delete by value

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$

16. CPython #1: PyBytesObject

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

8030f8429cb90b3fc145b994112e2dae8c4030e0

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$