Python

--- primary_color: steelblue --- ## Commentary How to comment in Python ? 1. [x] using `#` 1. [ ] using `//` 1. [ ] using `--` 1. [ ] using `%` ## Modules What's a Python **module** ? 1. [x] a file with a `.py` extension 1. [ ] a directory with an `__init__.py` file 1. [ ] a component of `pip` ## Packages What's a Python **package** ? 1. [ ] a file with a `.py` extension 1. [x] a directory with an `__init__.py` file 1. [ ] a component of `pip` ## Virtual environments What's the advantage of using virtual environments (venv, pipenv, virtualenv, and so on) ? > 2 good answers - [x] segregate dependencies of a project from system packages - [x] easily manage differents python version - [ ] simplify the installation of python packages - [ ] minimize the hard disk usage ## Package installation How can you install a python package ? > Let's consider we're using a debian-based linux here ;) - [x] `pip install ` - [x] `conda install ` - [x] `sudo apt install python-` - [ ] `python install ` ## Built-in : zip & range What is the result of the following code ? ```python for a, b in zip("toto", range(3)): print(a, b) ``` 1. [x] ```shell t 0 o 1 t 2 ``` 1. [ ] ```shell t 0 o 1 t 2 o 3 ``` 1. [ ] ```shell t 0 o 1 t 2 o 0 ``` ## Built-in : map & filter What is the result of the following code ? ```python t = [0, 5, 10, 15, 20, 25, 30] filtered_t = filter(lambda x: x % 2 == 1, t) print(list(map(print, filtered_t))) ``` 1. [x] ```shell 5 15 25 [None, None, None] ``` 1. [ ] ```shell [5, 15, 25] ``` 1. [ ] ```shell 5 15 25 [5, 15, 25] ``` ## Buit-in : string In python, strings are: 1. [x] immutable 1. [ ] mutable ## Built-in : dict In python, does dictionary preserve the insertion order ? > 2 good answers - [ ] no - [ ] yes, by design since python 1.0 - [x] yes, by CPython implementation since 3.6 - [x] yes, by design since 3.7 ## Function Suppose we have a function `f` and the following calls are valid: ```python f(alpha=2) f(1, 2, 3) f(1, beta=2) ``` What could be the signature of `f` ? > 2 good answers - [x] `def f(*args, alpha=1, beta=1):` - [x] `def f(*args, **kwargs):` - [ ] `def f(x, y, z, alpha=1, beta=1):` - [ ] `def f(*args, alpha, beta):` ## pip Select the right answers about pip - [x] `pip` is the standard package manager for python - [ ] `pip` is a virtual environment manager - [ ] `pip` is a registry to store python package ## conda Select the right answers about conda - [x] `conda` is a package manager for python - [x] `conda` is a virtual environment manager - [ ] `conda` is a registry to store python package ## pip vs conda Does `pip install ` and `conda install ` is always equivalent ? Are we sure that the installed packages are the same ? > Does `pip` and `conda` use the same package registry ? ;) - [ ] yes - [x] no ## pycache What's a `.pyc` file ? > 2 answers here - [x] a file created by the Python interpreter when a module is imported - [x] a file containing bytecode - [ ] a cython file ## Wh@t's this ? How do you call the instruction beggining by `@` in the following sample ? ```python @stuff def func(): pass ``` 1. [ ] annotation 1. [x] decorator ## Classes : Diamond problem Select the right answers about Python's inheritance 1. [ ] Python forbid multiple inheritance 1. [x] Python solves the diamond problem with a method resolution order 1. [ ] Python developer have to solve the diamond problem explicitly ## Classes : Attributes Consider the following code ```python class Foo: def __init__(self): self.a = 0 self._a = 1 self.__a = 2 foo = Foo() ``` Which of the following assert will pass ? > Beware of name mangling (see [PEP-8](https://peps.python.org/pep-0008/)) ! - [x] `assert(foo.a == 0)` - [x] `assert(foo._a == 1)` - [ ] `assert(foo.__a == 2)`