From e3c34aa9e4f7d6a28ea0ceb049214e9ab819fb59 Mon Sep 17 00:00:00 2001 From: abregman Date: Sat, 15 Oct 2022 16:30:49 +0300 Subject: [PATCH] Add a couple of questions --- README.md | 1578 +------------------------------------- topics/kubernetes/CKA.md | 75 +- 2 files changed, 64 insertions(+), 1589 deletions(-) diff --git a/README.md b/README.md index b1a7789..af73e0c 100644 --- a/README.md +++ b/README.md @@ -770,1582 +770,6 @@ The introduction of virtual machines allowed companies to deploy multiple busine Do we need virtual machines in the age of containers? Are they still relevant?
-#### Python - OOP - -
-Explain inheritance and how to use it in Python
-
- -
-Explain and demonstrate class attributes & instance attributes
- -In the following block of code `x` is a class attribute while `self.y` is a instance attribute - -``` -class MyClass(object): - x = 1 - - def __init__(self, y): - self.y = y -``` -
- -#### Python - Exceptions - -
-What is an error? What is an exception? What types of exceptions are you familiar with?
- -``` -# Note that you generally don't need to know the compiling process but knowing where everything comes from -# and giving complete answers shows that you truly know what you are talking about. - -Generally, every compiling process have a two steps. - - Analysis - - Code Generation. - - Analysis can be broken into: - 1. Lexical analysis (Tokenizes source code) - 2. Syntactic analysis (Check whether the tokens are legal or not, tldr, if syntax is correct) - - for i in 'foo' - ^ - SyntaxError: invalid syntax - - We missed ':' - - - 3. Semantic analysis (Contextual analysis, legal syntax can still trigger errors, did you try to divide by 0, - hash a mutable object or use an undeclared function?) - - 1/0 - ZeroDivisionError: division by zero - - These three analysis steps are the responsible for error handlings. - - The second step would be responsible for errors, mostly syntax errors, the most common error. - The third step would be responsible for Exceptions. - - As we have seen, Exceptions are semantic errors, there are many builtin Exceptions: - - ImportError - ValueError - KeyError - FileNotFoundError - IndentationError - IndexError - ... - - You can also have user defined Exceptions that have to inherit from the `Exception` class, directly or indirectly. - - Basic example: - - class DividedBy2Error(Exception): - def __init__(self, message): - self.message = message - - - def division(dividend,divisor): - if divisor == 2: - raise DividedBy2Error('I dont want you to divide by 2!') - return dividend / divisor - - division(100, 2) - - >>> __main__.DividedBy2Error: I dont want you to divide by 2! -``` -
- -
-Explain Exception Handling and how to use it in Python
- -**Exceptions:** Errors detected during execution are called Exceptions. - -**Handling Exception:** When an error occurs, or exception as we call it, Python will normally stop and generate an error message.
-Exceptions can be handled using `try` and `except` statement in python. - -**Example:** Following example asks the user for input until a valid integer has been entered.
-If user enter a non-integer value it will raise exception and using except it will catch that exception and ask the user to enter valid integer again. - - -```py -while True: - try: - a = int(input("please enter an integer value: ")) - break - except ValueError: - print("Ops! Please enter a valid integer value.") - -``` - -For more details about errors and exceptions follow this [https://docs.python.org/3/tutorial/errors.html](https://docs.python.org/3/tutorial/errors.html) - -
- -
-What is the result of running the following function? - -``` -def true_or_false(): - try: - return True - finally: - return False -``` -
-False -
- -#### Python Built-in functions - -
-Explain the following built-in functions (their purpose + use case example): - - * repr - * any - * all
-
- -
-What is the difference between repr function and str?
-
- -
-What is the __call__ method?
- -It is used to emulate callable objects. It allows a class instance to be called as a function. - -- Example code: - -``` -class Foo: - def __init__(self: object) -> None: - pass - def __call__(self: object) -> None: - print("Called!") - -f = Foo() -f() -``` - -- Result: - -``` -Called! -``` - -
- -
-Do classes has the __call__ method as well? What for?
-
- -
-What _ is used for in Python?
- -1. Translation lookup in i18n -2. Hold the result of the last executed expression or statement in the interactive interpreter. -3. As a general purpose "throwaway" variable name. For example: x, y, _ = get_data() (x and y are used but since we don't care about third variable, we "threw it away"). -
- -
-Explain what is GIL
- Python Global Interpreter Lock (GIL) is a type of process lock which is used by python whenever it deals with processes. Generally, Python only uses only one thread to execute the set of written statements. This means that in python only one thread will be executed at a time -
- -
-What is Lambda? How is it used?
- -A lambda expression is an 'anonymous' function, the difference from a normal defined function using the keyword `def`` is the syntax and usage. - -The syntax is: - -```lambda[parameters]: [expresion]``` - -**Examples:** - -* A lambda function add 10 with any argument passed. - -```py -x = lambda a: a + 10 -print(x(10)) -``` - -* An addition function - -```py -addition = lambda x, y: x + y -print(addition(10, 20)) -``` - -* Squaring function - -```py -square = lambda x : x ** 2 -print(square(5)) -``` -Generally it is considered a bad practice under PEP 8 to assign a lambda expresion, they are meant to be used as parameters and inside of other defined functions. - -
- -#### Properties - -
-Are there private variables in Python? How would you make an attribute of a class, private?
-
- -
-Explain the following: - -* getter -* setter -* deleter
-
- -
-Explain what is @property
-
- -
-How do you swap values between two variables?
- -``` -x, y = y, x -``` -
- -
-Explain the following object's magic variables: - - * __dict__ -
-
- -
-Write a function to return the sum of one or more numbers. The user will decide how many numbers to use
- -First you ask the user for the amount of numbers that will be use. Use a while loop that runs until amount_of_numbers becomes 0 through subtracting amount_of_numbers by one each loop. In the while loop you want ask the user for a number which will be added a variable each time the loop runs. - -``` -def return_sum(): - amount_of_numbers = int(input("How many numbers? ")) - total_sum = 0 - while amount_of_numbers != 0: - num = int(input("Input a number. ")) - total_sum += num - amount_of_numbers -= 1 - return total_sum - -``` -
- -
-Print the average of [2, 5, 6]. It should be rounded to 3 decimal places
- -``` -li = [2, 5, 6] -print("{0:.3f}".format(sum(li)/len(li))) -``` -
- -#### Python - Lists - -
-What is a tuple in Python? What is it used for?
- -A tuple is a built-in data type in Python. It's used for storing multiple items in a single variable. -
- -
-List, like a tuple, is also used for storing multiple items. What is then, the difference between a tuple and a list?
- -List, as opposed to a tuple, is a mutable data type. It means we can modify it and at items to it. -
- -
-How to add the number 2 to the list x = [1, 2, 3]
- -`x.append(2)` -
- -
-How to get the last element of a list?
- -`some_list[-1]` -
- -
-How to add the items of [1, 2, 3] to the list [4, 5, 6]?
-x = [4, 5, 6] -x.extend([1, 2, 3]) - -Don't use `append` unless you would like the list as one item. -
- -
-How to remove the first 3 items from a list?
- -`my_list[0:3] = []` -
- -
-How to insert an item to the beginning of a list? What about two items?
- -- One item: - -``` -numbers = [1, 2, 3, 4, 5] -numbers.insert(0, 0) -print(numbers) -``` - -- Multiple items or list: - -``` -numbers_1 = [2, 3, 4, 5] -numbers_2 = [0, 1] -numbers_1 = numbers_2 + numbers_1 -print(numbers_1) -``` - -
- -
-How to sort list by the length of items?
- -``` -sorted_li = sorted(li, key=len) -``` - -Or without creating a new list: - -``` -li.sort(key=len) -``` -
- -
-Do you know what is the difference between list.sort() and sorted(list)?
- -* sorted(list) will return a new list (original list doesn't change) -* list.sort() will return None but the list is change in-place - -* sorted() works on any iterable (Dictionaries, Strings, ...) -* list.sort() is faster than sorted(list) in case of Lists -
- -
-Convert every string to an integer: [['1', '2', '3'], ['4', '5', '6']]
- -``` -nested_li = [['1', '2', '3'], ['4', '5', '6']] -[[int(x) for x in li] for li in nested_li] -``` -
- -
-How to merge two sorted lists into one sorted list?
- -``` -sorted(li1 + li2) -``` - -Another way: - -``` -i, j = 0 -merged_li = [] - -while i < len(li1) and j < len(li2): - if li1[i] < li2[j]: - merged_li.append(li1[i]) - i += 1 - else: - merged_li.append(li2[j]) - j += 1 - -merged_li = merged_li + merged_li[i:] + merged_li[j:] -``` -
- -
-How to check if all the elements in a given lists are unique? so [1, 2, 3] is unique but [1, 1, 2, 3] is not unique because 1 exists twice
- - -There are many ways of solving this problem:
-# Note: :list and -> bool are just python typings, they are not needed for the correct execution of the algorithm. - -Taking advantage of sets and len: - -``` -def is_unique(l:list) -> bool: - return len(set(l)) == len(l) -``` - -This one is can be seen used in other programming languages. - -``` -def is_unique2(l:list) -> bool: - seen = [] - - for i in l: - if i in seen: - return False - seen.append(i) - return True -``` - -Here we just count and make sure every element is just repeated once. - -``` -def is_unique3(l:list) -> bool: - for i in l: - if l.count(i) > 1: - return False - return True -``` - -This one might look more convulated but hey, one liners. - -``` -def is_unique4(l:list) -> bool: - return all(map(lambda x: l.count(x) < 2, l)) -``` -
- -
-You have the following function - -``` -def my_func(li = []): - li.append("hmm") - print(li) -``` - -If we call it 3 times, what would be the result each call? -
- -``` -['hmm'] -['hmm', 'hmm'] -['hmm', 'hmm', 'hmm'] -``` -
- - -
-How to iterate over a list?
- -``` -for item in some_list: - print(item) -``` -
- -
-How to iterate over a list with indexes?
- -``` -for i, item in enumerate(some_list): - print(i) -``` -
- -
-How to start list iteration from 2nd index?
- -Using range like this - -``` -for i in range(1, len(some_list)): - some_list[i] -``` - -Another way is using slicing - -``` -for i in some_list[1:]: -``` -
- -
-How to iterate over a list in reverse order?
- -Method 1 -``` -for i in reversed(li): - ... -``` - -Method 2 -``` -n = len(li) - 1 -while n > 0: - ... - n -= 1 -``` -
- -
-Sort a list of lists by the second item of each nested list
- -``` -li = [[1, 4], [2, 1], [3, 9], [4, 2], [4, 5]] - -sorted(li, key=lambda l: l[1]) -``` - -or - -``` -li.sort(key=lambda l: l[1) -``` -
- -
-Combine [1, 2, 3] and ['x', 'y', 'z'] so the result is [(1, 'x'), (2, 'y'), (3, 'z')]
- -``` -nums = [1, 2, 3] -letters = ['x', 'y', 'z'] - -list(zip(nums, letters)) -``` -
- -
-What is List Comprehension? Is it better than a typical loop? Why? Can you demonstrate how to use it?
- -From [Docs](https://docs.python.org/3/tutorial/datastructures.html#list-comprehensions): "List comprehensions provide a concise way to create lists. Common applications are to make new lists where each element is the result of some operations applied to each member of another sequence or iterable, or to create a subsequence of those elements that satisfy a certain condition.". - -It's better because they're compact, faster and have better readability. - -- For loop: - -``` -number_lists = [[1, 7, 3, 1], [13, 93, 23, 12], [123, 423, 456, 653, 124]] -odd_numbers = [] -for number_list in number_lists: - for number in number_list: - if number % 2 == 0: - odd_numbers.append(number) -print(odd_numbers) -``` - -- List comprehesion: - -``` -number_lists = [[1, 7, 3, 1], [13, 93, 23, 12], [123, 423, 456, 653, 124]] -odd_numbers = [number for number_list in number_lists for number in number_list if number % 2 == 0] -print(odd_numbers) -``` - -
- -
-You have the following list: [{'name': 'Mario', 'food': ['mushrooms', 'goombas']}, {'name': 'Luigi', 'food': ['mushrooms', 'turtles']}] - Extract all type of foods. Final output should be: {'mushrooms', 'goombas', 'turtles'}
- -``` -brothers_menu = \ -[{'name': 'Mario', 'food': ['mushrooms', 'goombas']}, {'name': 'Luigi', 'food': ['mushrooms', 'turtles']}] - -# "Classic" Way -def get_food(brothers_menu) -> set: - temp = [] - - for brother in brothers_menu: - for food in brother['food']: - temp.append(food) - - return set(temp) - -# One liner way (Using list comprehension) -set([food for bro in x for food in bro['food']]) -``` -
- -#### Python - Dictionaries - -
-How to create a dictionary?
- -my_dict = dict(x=1, y=2) -OR -my_dict = {'x': 1, 'y': 2} -OR -my_dict = dict([('x', 1), ('y', 2)]) -
- -
-How to remove a key from a dictionary?
- -del my_dict['some_key'] -you can also use `my_dict.pop('some_key')` which returns the value of the key. -
- -
-How to sort a dictionary by values?
- -``` -{k: v for k, v in sorted(x.items(), key=lambda item: item[1])} -``` -
- -
-How to sort a dictionary by keys?
- -``` -dict(sorted(some_dictionary.items())) -``` -
- -
-How to merge two dictionaries?
- -``` -some_dict1.update(some_dict2) -``` -
- - -
-Convert the string "a.b.c" to the dictionary {'a': {'b': {'c': 1}}}
- -``` -output = {} -string = "a.b.c" -path = string.split('.') -target = reduce(lambda d, k: d.setdefault(k, {}), path[:-1], output) -target[path[-1]] = 1 -print(output) -``` -
- -##### Common Algorithms Implementation - -
-Can you implement "binary search" in Python?
- -[Solution](coding/python/binary_search.py) -
- -#### Python Files - -
-How to write to a file?
- -``` -with open('file.txt', 'w') as file: - file.write("My insightful comment") -``` -
- -
-Sum all the integers in a given file
-
- -
-Print a random line of a given file
-
- -
-Print every 3rd line of a given file
-
- -
-Print the number of lines in a given file
-
- -
-Print the number of of words in a given file
-
- -
-Can you write a function which will print all the file in a given directory? including sub-directories
-
- -
-Write a dictionary (variable) to a file
- -``` -import json - -with open('file.json', 'w') as f: - f.write(json.dumps(dict_var)) -``` -
- -#### Python OS - -
-How to print current working directory?
- - import os - - print(os.getcwd()) - -
- -
-Given the path /dir1/dir2/file1 print the file name (file1)
- - import os - - print(os.path.basename('/dir1/dir2/file1')) - - # Another way - print(os.path.split('/dir1/dir2/file1')[1]) - -
- -
-Given the path /dir1/dir2/file1 - -1. Print the path without the file name (/dir1/dir2) -2. Print the name of the directory where the file resides (dir2) -
- - import os - - ## Part 1. - # os.path.dirname gives path removing the end component - dirpath = os.path.dirname('/dir1/dir2/file1') - print(dirpath) - - ## Part 2. - print(os.path.basename(dirpath)) - -
- -
-How do you execute shell commands using Python?
-
- -
-How do you join path components? for example /home and luig will result in /home/luigi
-
- -
-How do you remove non-empty directory?
-
- -#### Python Regex - -
-How do you perform regular expressions related operations in Python? (match patterns, substitute strings, etc.)
- -Using the re module -
- -
-How to find all the IP addresses in a variable? How to find them in a file?
-
- -#### Python Strings - -
-Find the first repeated character in a string
- -While you iterate through the characters, store them in a dictionary and check for every character whether it's already in the dictionary. - -``` -def firstRepeatedCharacter(str): - chars = {} - for ch in str: - if ch in chars: - return ch - else: - chars[ch] = 0 -``` -
- -
-How to extract the unique characters from a string? for example given the input "itssssssameeeemarioooooo" the output will be "mrtisaoe"
- -``` -x = "itssssssameeeemarioooooo" -y = ''.join(set(x)) -``` -
- -
-Find all the permutations of a given string
- -``` -def permute_string(string): - - if len(string) == 1: - return [string] - - permutations = [] - for i in range(len(string)): - swaps = permute_string(string[:i] + string[(i+1):]) - for swap in swaps: - permutations.append(string[i] + swap) - - return permutations - -print(permute_string("abc")) -``` - -Short way (but probably not acceptable in interviews): - -``` -from itertools import permutations - -[''.join(p) for p in permutations("abc")] -``` - -Detailed answer can be found here: http://codingshell.com/python-all-string-permutations - -
- -
-How to check if a string contains a sub string?
-
- -
-Find the frequency of each character in string
-
- -
-Count the number of spaces in a string
- -You can use the "count" method like this: - -```python - -ImAString.count(" ") - -``` - -
- -
-Given a string, find the N most repeated words
-
- -
-Given the string (which represents a matrix) "1 2 3\n4 5 6\n7 8 9" create rows and colums variables (should contain integers, not strings)
-
- -
-What is the result of each of the following? - -``` ->> ', '.join(["One", "Two", "Three"]) ->> " ".join("welladsadgadoneadsadga".split("adsadga")[:2]) ->> "".join(["c", "t", "o", "a", "o", "q", "l"])[0::2] -``` -
- -``` ->>> 'One, Two, Three' ->>> 'well done' ->>> 'cool' -``` -
- -
-If x = "pizza", what would be the result of x[::-1]?
- -It will reverse the string, so x would be equal to `azzip`. -
- -
-Reverse each word in a string (while keeping the order)
-
- -
-What is the output of the following code: "".join(["a", "h", "m", "a", "h", "a", "n", "q", "r", "l", "o", "i", "f", "o", "o"])[2::3]
- -mario -
- -#### Python Iterators - -
-What is an iterator?
-
- -#### Python Misc - -
-Explain data serialization and how do you perform it with Python
-
- -
-How do you handle argument parsing in Python?
-
- -
-What is a generator? Why using generators?
-
- -
-What would be the output of the following block? - -``` -for i in range(3, 3): - print(i) -``` -
- -No output :) -
- -
-What is yeild? When would you use it?
-
- -
-Explain the following types of methods and how to use them: - - * Static method - * Class method - * instance method
-
- -
-How to reverse a list?
-
- -
-How to combine list of strings into one string with spaces between the strings
-
- -
-You have the following list of nested lists: [['Mario', 90], ['Geralt', 82], ['Gordon', 88]] How to sort the list by the numbers in the nested lists?
- -One way is: - -the_list.sort(key=lambda x: x[1]) -
- -
-Explain the following: - - * zip() - * map() - * filter()
-
- -#### Python - Slicing - -For the following slicing exercises, assume you have the following list: `my_list = [8, 2, 1, 10, 5, 4, 3, 9]` - -
-What is the result of `my_list[0:4]`?
-
- -
-What is the result of `my_list[5:6]`?
-
- -
-What is the result of `my_list[5:5]`?
-
- -
-What is the result of `my_list[::-1]`?
-
- -
-What is the result of `my_list[::3]`?
-
- -
-What is the result of `my_list[2:]`?
-
- -
-What is the result of `my_list[:3]`?
-
- -#### Python Debugging - -
-How do you debug Python code?
- -pdb :D -
- -
-How to check how much time it took to execute a certain script or block of code?
-
- -
-What empty return returns?
- - -Short answer is: It returns a None object. - -We could go a bit deeper and explain the difference between - -``` -def a (): - return - ->>> None -``` - -And - -``` -def a (): - pass - ->>> None -``` -Or we could be asked this as a following question, since they both give the same result. - -We could use the dis module to see what's going on: - -``` - 2 0 LOAD_CONST 0 (", line 2>) - 2 LOAD_CONST 1 ('a') - 4 MAKE_FUNCTION 0 - 6 STORE_NAME 0 (a) - - 5 8 LOAD_CONST 2 (", line 5>) - 10 LOAD_CONST 3 ('b') - 12 MAKE_FUNCTION 0 - 14 STORE_NAME 1 (b) - 16 LOAD_CONST 4 (None) - 18 RETURN_VALUE - -Disassembly of ", line 2>: - 3 0 LOAD_CONST 0 (None) - 2 RETURN_VALUE - -Disassembly of ", line 5>: - 6 0 LOAD_CONST 0 (None) - 2 RETURN_VALUE -``` - -An empty return is exactly the same as return None and functions without any explicit return -will always return None regardless of the operations, therefore - - -``` -def sum(a, b): - global c - c = a + b - ->>> None -``` -
- -
-How to improve the following block of code? - -``` -li = [] -for i in range(1, 10): - li.append(i) -``` -
- -``` -[i for i in range(1, 10)] -``` -
- -
-Given the following function - -``` -def is_int(num): - if isinstance(num, int): - print('Yes') - else: - print('No') -``` -What would be the result of is_int(2) and is_int(False)? -
-
- -#### Python - Linked List - -
-Can you implement a linked list in Python?
- -The reason we need to implement in the first place, it's because a linked list isn't part of Python standard library.
-To implement a linked list, we have to implement two structures: The linked list itself and a node which is used by the linked list. - -Let's start with a node. A node has some value (the data it holds) and a pointer to the next node - -``` -class Node(object): - def __init__(self, data): - self.data = data - self.next = None -``` - -Now the linked list. An empty linked list has nothing but an empty head. - -``` -class LinkedList(object): - def __init__(self): - self.head = None -``` - -Now we can start using the linked list - -``` -ll = Linkedlist() -ll.head = Node(1) -ll.head.next = Node(2) -ll.head.next.next = Node(3) -``` - -What we have is: - ----- ----- ---- -| 1 | -> | 2 | -> | 3 | ----- ----- ----- - -Usually, more methods are implemented, like a push_head() method where you insert a node at the beginning of the linked list - -``` -def push_head(self, value): - new_node = Node(value) - new_node.next = self.head - self.head = new_node -``` -
- -
-Add a method to the Linked List class to traverse (print every node's data) the linked list
- -def print_list(self): - node = self.head - while(node): - print(node.data) - node = node.next -
- -
-Write a method to that will return a boolean based on whether there is a loop in a linked list or not
- -Let's use the Floyd's Cycle-Finding algorithm: - -``` -def loop_exists(self): - one_step_p = self.head - two_steps_p = self.head - while(one_step_p and two_steps_p and two_steps_p.next): - one_step_p = self.head.next - two_step_p = self.head.next.next - if (one_step_p == two_steps_p): - return True - return False -``` -
- -#### Python - Stack - -
-Implement Stack in Python
-
- -#### Python Testing - -
-What is your experience with writing tests in Python?
-
- -
-What is PEP8? Give an example of 3 style guidelines
- -PEP8 is a list of coding conventions and style guidelines for Python - -5 style guidelines: - - 1. Limit all lines to a maximum of 79 characters. - 2. Surround top-level function and class definitions with two blank lines. - 3. Use commas when making a tuple of one element - 4. Use spaces (and not tabs) for indentation - 5. Use 4 spaces per indentation level -
- -
-How to test if an exception was raised?
-
- -
-What assert does in Python?
-
- -
-Explain mocks
-
- -
-How do you measure execution time of small code snippets?
-
- -
-Why one shouldn't use assert in non-test/production code?
-
- -#### Flask - -
-Can you describe what is Django/Flask and how you have used it? Why Flask and not Django? (or vice versa)
-
- -
-What is a route?
-As every web framework, Flask provides a route functionality that lets you serve a content of a given URL. - -There are multiple ways to map a URL with a function in Python. - -- Decorator: you can use python decorators. In this case we're using `app`. This `app` decorator is the instance of the `Flask` class. And route it's a method of this class. - -``` -@app.route('/') -def home(): - return 'main website' -``` - -- `add_url_rule` method: This is a method of the Flask class. We can also use it for map the URL with a function. - -``` -def home(): - return 'main website' - -app.add_url_rule('/', view_func=home) -``` - -
- -
-What is a blueprint in Flask?
-
- -
-What is a template?
-
- -#### zip - -
-Given x = [1, 2, 3], what is the result of list(zip(x))?
- -``` -[(1,), (2,), (3,)] -``` -
- -
-What is the result of each of the following: - -``` -list(zip(range(5), range(50), range(50))) -list(zip(range(5), range(50), range(-2))) -``` -
- -``` -[(0, 0, 0), (1, 1, 1), (2, 2, 2), (3, 3, 3), (4, 4, 4)] -[] -``` -
- -#### Python Descriptors - -
-Explain Descriptors
- -Read about descriptors [here](https://docs.python.org/3/howto/descriptor.html) -
- -
-What would be the result of running a.num2 assuming the following code - -``` -class B: - def __get__(self, obj, objtype=None): - reuturn 10 - -class A: - num1 = 2 - num2 = Five() -``` -
-10 -
- -
-What would be the result of running some_car = Car("Red", 4) assuming the following code - -``` -class Print: - - def __get__(self, obj, objtype=None): - value = obj._color - print("Color was set to {}".format(valie)) - return value - - def __set__(self, obj, value): - print("The color of the car is {}".format(value)) - obj._color = value - -class Car: - - color = Print() - - def __ini__(self, color, age): - self.color = color - self.age = age -``` -
-An instance of Car class will be created and the following will be printed: "The color of the car is Red" -
- -#### Python Misc - -
-How can you spawn multiple processes with Python?
-
- -
-Implement simple calculator for two numbers
- -``` -def add(num1, num2): - return num1 + num2 - - -def sub(num1, num2): - return num1 - num2 - - -def mul(num1, num2): - return num1*num2 - - -def div(num1, num2): - return num1 / num2 - -operators = { - '+': add, - '-': sub, - '*': mul, - '/': div -} - -if __name__ == '__main__': - operator = str(input("Operator: ")) - num1 = int(input("1st number: ")) - num2 = int(input("2nd number: ")) - print(operators[operator](num1, num2)) -``` -
- -
-What data types are you familiar with that are not Python built-in types but still provided by modules which are part of the standard library?
- -This is a good reference https://docs.python.org/3/library/datatypes.html -
- -
-Explain what is a decorator
- -In python, everything is an object, even functions themselves. Therefore you could pass functions as arguments -for another function eg; - -``` -def wee(word): - return word - -def oh(f): - return f + "Ohh" - ->>> oh(wee("Wee")) -<<< Wee Ohh -``` - -This allows us to control the before execution of any given function and if we added another function as wrapper, -(a function receiving another function that receives a function as parameter) we could also control the after execution. - -Sometimes we want to control the before-after execution of many functions and it would get tedious to write - - f = function(function_1()) - f = function(function_1(function_2(*args))) - -every time, that's what decorators do, they introduce syntax to write all of this on the go, using the keyword '@'. - -
- -
-Can you show how to write and use decorators?
- - -These two decorators (ntimes and timer) are usually used to display decorators functionalities, you can find them in lots of -tutorials/reviews. I first saw these examples two years ago in pyData 2017. https://www.youtube.com/watch?v=7lmCu8wz8ro&t=3731s - -``` -Simple decorator: - -def deco(f): - print(f"Hi I am the {f.__name__}() function!") - return f - -@deco -def hello_world(): - return "Hi, I'm in!" - -a = hello_world() -print(a) - ->>> Hi I am the hello_world() function! - Hi, I'm in! -``` - -This is the simplest decorator version, it basically saves us from writting a = deco(hello_world()). -But at this point we can only control the before execution, let's take on the after: - -``` -def deco(f): - def wrapper(*args, **kwargs): - print("Rick Sanchez!") - func = f(*args, **kwargs) - print("I'm in!") - return func - return wrapper - -@deco -def f(word): - print(word) - -a = f("************") ->>> Rick Sanchez! - ************ - I'm in! -``` - -deco receives a function -> f -wrapper receives the arguments -> *args, **kwargs - -wrapper returns the function plus the arguments -> f(*args, **kwargs) -deco returns wrapper. - -As you can see we conveniently do things before and after the execution of a given function. - -For example, we could write a decorator that calculates the execution time of a function. - -``` -import time -def deco(f): - def wrapper(*args, **kwargs): - before = time.time() - func = f(*args, **kwargs) - after = time.time() - print(after-before) - return func - return wrapper - -@deco -def f(): - time.sleep(2) - print("************") - -a = f() ->>> 2.0008859634399414 -``` - -Or create a decorator that executes a function n times. - -``` -def n_times(n): - def wrapper(f): - def inner(*args, **kwargs): - for _ in range(n): - func = f(*args, **kwargs) - return func - return inner - return wrapper - -@n_times(4) -def f(): - print("************") - -a = f() - ->>>************ - ************ - ************ - ************ -``` - -
- -
-Write a decorator that calculates the execution time of a function
-
- -
-Write a script which will determine if a given host is accessible on a given port
-
- -
-Are you familiar with Dataclasses? Can you explain what are they used for?
-
- -
-You wrote a class to represent a car. How would you compare two cars instances if two cars are equal if they have the same model and color?
- -``` -class Car: - def __init__(self, model, color): - self.model = model - self.color = color - - def __eq__(self, other): - if not isinstance(other, Car): - return NotImplemented - return self.model == other.model and self.color == other.color - ->> a = Car('model_1', 'red') ->> b = Car('model_2', 'green') ->> c = Car('model_1', 'red') ->> a == b -False ->> a == c -True -``` -
- -
-Explain Context Manager
-
- -
-Tell me everything you know about concurrency in Python
-
- -
-Explain the Buffer Protocol
-
- -
-Do you have experience with web scraping? Can you describe what have you used and for what?
-
- -
-Can you implement Linux's tail command in Python? Bonus: implement head as well
-
- -
-You have created a web page where a user can upload a document. But the function which reads the uploaded files, runs for a long time, based on the document size and user has to wait for the read operation to complete before he/she can continue using the web site. How can you overcome this?
-
- -
-How yield works exactly?
-
- ## Monitoring
@@ -5566,7 +3990,7 @@ If you are looking for a way to prepare for a certain exam this is the section f #### Kubernetes -* [Certified Kubernetes Administrator (CKA)](certificates/cka.md) (Latest update: 2020) +* [Certified Kubernetes Administrator (CKA)](topics/kubernetes/CKA.md) (Latest update: 2022) ## Other DevOps Projects diff --git a/topics/kubernetes/CKA.md b/topics/kubernetes/CKA.md index dbe008a..1c7eeb8 100644 --- a/topics/kubernetes/CKA.md +++ b/topics/kubernetes/CKA.md @@ -2,10 +2,11 @@ - [CKA (Certified Kubernetes Administrator)](#cka-certified-kubernetes-administrator) - [Setup](#setup) - - [Kubernetes Nodes](#kubernetes-nodes) - [Pods](#pods) - [Troubleshooting Pods](#troubleshooting-pods) - [Namespaces](#namespaces) + - [Nodes](#nodes) + - [Services](#services) ## Setup @@ -24,16 +25,6 @@ alias kr=kubectl run alias kg=kubectl get ``` -## Kubernetes Nodes - -
-Run a command to view all nodes of the cluster
- -`kubectl get nodes` - -Note: create an alias (`alias k=kubectl`) and get used to `k get no` -
- ## Pods
@@ -98,7 +89,33 @@ k create -f pod.yaml with `--dry-run` flag which will not actually create it, but it will test it and you can find this way any syntax issues. -`kubectl create -f YAML_FILE --dry-run` +`k create -f YAML_FILE --dry-run` +
+ +
+How to check which image a certain Pod is using?
+ +`k describe po | grep -i image` +
+ +
+How to check how many containers run in signle Pod?
+ +`k get po POD_NAME` and see the number under "READY" column. + +You can also run `k describe po POD_NAME` +
+ +
+Run a Pod called "remo" with the the latest redis image and the label 'year=2017'
+ +`k run remo --image=redis:latest -l year=2017` +
+ +
+List pods and their labels
+ +`k get po --show-labels`
### Troubleshooting Pods @@ -130,10 +147,44 @@ Most likely you didn't write correctly the name of the image you try to pull and You can confirm with `kubectl describe po POD_NAME`
+
+How to check on which node a certain Pod is running?
+ +`k get po POD_NAME -o wide` +
+ ## Namespaces
List all the namespaces
`k get ns` +
+ +
+Create a namespace called 'alle'
+ +`k create ns alle` +
+ +## Nodes + +
+Run a command to view all nodes of the cluster
+ +`kubectl get nodes` + +Note: create an alias (`alias k=kubectl`) and get used to `k get no` +
+ +
+Create a list of all nodes in JSON format and store it in a file called "some_nodes.json"
+ +`k get nodes -o json > some_nodes.json` +
+ +## Services + +
+Create an internal service called "sevi" to expose the app 'web' on port 1991
\ No newline at end of file