Python Interviews: Tips and Practice
In today's IT industry, Python has become a very popular programming language. It has attracted countless developers with its concise and clear syntax, powerful library support and wide application fields. However, mastering Python is not an easy task, especially during the interview process. This article will give you some tips and practical experience about Python interviews to help you stand out in the interview.
1. Basic knowledge of Python
1. Features of Python
Python is an interpreted, object-oriented, high-level programming language with dynamic data types. It has the following characteristics:
- Concise and clear: Python syntax is simple, the code is highly readable and easy to maintain.
- Cross-platform: Python programs can run on different operating systems, just write the code once.
- Object-oriented: Python supports object-oriented features such as encapsulation, inheritance, and polymorphism.
- Abundant third-party libraries: Python has a large number of third-party libraries, covering various fields, such as data science, web crawling, machine learning, etc.
- Scalability: Python can be mixed with other programming languages (such as C, C++, Java, etc.) to improve program performance.
2. Python's basic data types
Python has a variety of basic data types, which fall into four categories:
- Numerical type: int (integer), float (floating point number), complex (complex number).
- string: str(string).
- list: list(list).
- tuple: tuple (tuple).
- set: set (set).
- Dictionary: dict(dictionary).
3. Python operators
Python supports a variety of operators, including arithmetic operators, relational operators, logical operators, bitwise operators, assignment operators, conditional operators, etc.
4. Python conditional statement
There are three kinds of conditional statements in Python: if-else, elif-else, and the ternary operator (?:).
5. Python loop statement
Python has two kinds of loop statements: for loop and while loop. In addition, there is an enhanced for loop (for-each loop).
6. Python method
A method is a block of code with a specific function that can be called by other methods. Methods in Python have the following characteristics:
- Access modifiers: public, private, protected, default (do not write).
- Return value type: void (no return value), basic data type, reference data type or custom class.
- Method name: follow the camel case naming convention.
- Parameter list: There can be multiple parameters, each parameter is separated by a comma. Parameters can have a name and type, or be omitted.
- Method body: Surrounded by curly braces {}, it contains a series of statements.
7. Python exception handling
Exception handling in Python mainly includes three keywords: try-except-finally. When an exception occurs in the program, you can use the try-catch statement to catch and handle the exception. The code in the finally block executes regardless of whether an exception occurs.
8. Python modules and packages
A module is a file containing related functions and variables, which can be imported into the program for use through the import statement. A package is a directory containing multiple modules that can be imported using the dot operator. Commonly used Python standard libraries include os, sys, re, json, etc.
Two, Python object-oriented programming
1. The concept of class and object
Class is the basic concept of object-oriented programming, and it is an abstract data type used to describe objects with the same properties and methods. An object is an instance of a class and has the properties and methods defined by the class.
2. Construction method and destruction method
The construction method is used to initialize the properties of the object, usually implemented in the first method in the class definition; the destructor method is used to release the resources occupied by the object, usually implemented in the last method in the class definition. Both constructors and destructors are represented as class methods using the @classmethod decorator.
3. Inheritance and polymorphism
Inheritance is a way to create a new class. Subclasses can inherit the properties and methods of the parent class; polymorphism means that objects of different classes can use the same interface to operate, and the specific implementation is determined by the subclass. Inheritance and polymorphism are core concepts of object-oriented programming.