README.md

0x02. Python - import & modules

• By Guillaume

Resources

Read or watch:

• Modules
• Command line arguments
• Pycodestyle -- Style Guide for Python Code

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
• How to import functions from another file
• How to use imported functions
• How to create a module
• How to use the built-in function dir()
• How to prevent code in your script from being executed when imported
• How to use command line arguments with your Python programs

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

Quiz questions

Show

Tasks

0. Import a simple function from a simple file

mandatory

Write a program that imports the function def add(a, b): from the file add_0.py and prints the result of the addition 1 + 2 = 3

• You have to use print function with string format to display integers
• You have to assign:
  • the value 1 to a variable called a
  • the value 2 to a variable called b
  • and use those two variables as arguments when calling the functions add and print
• a and b must be defined in 2 different lines: a = 1 and another b = 2
• Your program should print: <a value> + <b value> = <add(a, b) value> followed with a new line
• You can only use the word add_0 once in your code
• You are not allowed to use * for importing or __import__
• Your code should not be executed when imported - by using __import__, like the example below

guillaume@ubuntu:~/0x02$ cat add_0.py
#!/usr/bin/python3
def add(a, b):
    """My addition function

    Args:
        a: first integer
        b: second integer

    Returns:
        The return value. a + b
    """
    return (a + b)

guillaume@ubuntu:~/0x02$ ./0-add.py
1 + 2 = 3
guillaume@ubuntu:~/0x02$ cat 0-import_add.py
__import__("0-add")
guillaume@ubuntu:~/0x02$ python3 0-import_add.py
guillaume@ubuntu:~/0x02$

Repo:

• GitHub repository: alx-higher_level_programming
• Directory: 0x02-python-import_modules
• File: 0-add.py

1. My first toolbox!

mandatory

Write a program that imports functions from the file calculator_1.py, does some Maths, and prints the result.

• Do not use the function print (with string format to display integers) more than 4 times
• You have to define:
  • the value 10 to a variable a
  • the value 5 to a variable b
  • and use those two variables only, as arguments when calling functions (including print)
• a and b must be defined in 2 different lines: a = 10 and another b = 5
• Your program should call each of the imported functions. See example below for format
• the word calculator_1 should be used only once in your file
• You are not allowed to use * for importing or __import__
• Your code should not be executed when imported

guillaume@ubuntu:~/0x02$ cat calculator_1.py
#!/usr/bin/python3
def add(a, b):
    """My addition function

    Args:
        a: first integer
        b: second integer

    Returns:
        The return value. a + b
    """
    return (a + b)

def sub(a, b):
    """My subtraction function

    Args:
        a: first integer
        b: second integer

    Returns:
        The return value. a - b
    """
    return (a - b)

def mul(a, b):
    """My multiplication function

    Args:
        a: first integer
        b: second integer

    Returns:
        The return value. a * b
    """
    return (a * b)

def div(a, b):
    """My division function

    Args:
        a: first integer
        b: second integer

    Returns:
        The return value. a / b
    """
    return int(a / b)

guillaume@ubuntu:~/0x02$ ./1-calculation.py
10 + 5 = 15
10 - 5 = 5
10 * 5 = 50
10 / 5 = 2
guillaume@ubuntu:~/0x02$

Repo:

• GitHub repository: alx-higher_level_programming
• Directory: 0x02-python-import_modules
• File: 1-calculation.py

2. How to make a script dynamic!

mandatory

Write a program that prints the number of and the list of its arguments.

• The output should be:
  • Number of argument(s) followed by argument (if number is one) or arguments (otherwise), followed by
  • : (or . if no arguments were passed) followed by
  • a new line, followed by (if at least one argument),
  • one line per argument:
    • the position of the argument (starting at 1) followed by :, followed by the argument value and a new line
• Your code should not be executed when imported
• The number of elements of argv can be retrieved by using: len(argv)
• You do not have to fully understand lists yet, but imagine that argv can be used just like a C array: you can use an index to walk through it. There are other ways (which will be preferred for future project tasks), if you know them you can use them.

guillaume@ubuntu:~/0x02$ ./2-args.py
0 arguments.
guillaume@ubuntu:~/0x02$ ./2-args.py Hello
1 argument:
1: Hello
guillaume@ubuntu:~/0x02$ ./2-args.py Hello Welcome To The Best School
6 arguments:
1: Hello
2: Welcome
3: To
4: The
5: Best
6: School
guillaume@ubuntu:~/0x02$

Repo:

• GitHub repository: alx-higher_level_programming
• Directory: 0x02-python-import_modules
• File: 2-args.py

3. Infinite addition

mandatory

Write a program that prints the result of the addition of all arguments

• The output should be the result of the addition of all arguments, followed by a new line
• You can cast arguments into integers by using int() (you can assume that all arguments can be casted into integers)
• Your code should not be executed when imported

guillaume@ubuntu:~/0x02$ ./3-infinite_add.py
0
guillaume@ubuntu:~/0x02$ ./3-infinite_add.py 79 10
89
guillaume@ubuntu:~/0x02$ ./3-infinite_add.py 79 10 -40 -300 89
-162
guillaume@ubuntu:~/0x02$

Last but not least, your program should also handle big numbers. And the good news is: if your program works for the above example, it will work for the following example:

guillaume@ubuntu:~/0x02$ ./3-infinite_add.py 1111111111111111111111111111111111111111111111111111111111112222222222222222222222222222222222223435467866765443534434222222254444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555666666666666666666666666666666777777777777777777777777777777888888888888888888888888888888899999999999999999999999990000000000000000000 11111111111111111111111111111111111111111111111111222222222222222222222222222333333333333333333334567788888899999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999
11111111111111111111111111111111111111111111111111222222222222222222222222222333333333333333333334568900000011111111111111111111111111111111111111111111111111112222222222222222222222222222222222223435467866765443534434222222254444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555666666666666666666666666666666777777777777777777777777777777888888888888888888888888888888899999999999999999999999989999999999999999999
guillaume@ubuntu:~/0x02$

Remember how you did (or did not) do it in C? #pythoniscool

Repo:

• GitHub repository: alx-higher_level_programming
• Directory: 0x02-python-import_modules
• File: 3-infinite_add.py

4. Who are you?

mandatory

Write a program that prints all the names defined by the compiled module hidden_4.pyc (please download it locally).

• You should print one name per line, in alpha order
• You should print only names that do not start with __
• Your code should not be executed when imported
• Make sure you are running your code in Python3.8.x (hidden_4.pyc has been compiled with this version)

guillaume@ubuntu:~/0x02$ curl -Lso "hidden_4.pyc" "https://github.com/holbertonschool/0x02.py/raw/master/hidden_4.pyc"
guillaume@ubuntu:~/0x02$ ./4-hidden_discovery.py | sort
my_secret_santa
print_hidden
print_school
guillaume@ubuntu:~/0x02$

Repo:

• GitHub repository: alx-higher_level_programming
• Directory: 0x02-python-import_modules
• File: 4-hidden_discovery.py

5. Everything can be imported

mandatory

Write a program that imports the variable a from the file variable_load_5.py and prints its value.

• You are not allowed to use * for importing or __import__
• Your code should not be executed when imported

guillaume@ubuntu:~/0x02$ cat variable_load_5.py
#!/usr/bin/python3
a = 98
"""Simple variable
"""

guillaume@ubuntu:~/0x02$ ./5-variable_load.py
98
guillaume@ubuntu:~/0x02$

Repo:

• GitHub repository: alx-higher_level_programming
• Directory: 0x02-python-import_modules
• File: 5-variable_load.py