Preface
In the process of learning Python, novices often encounter common pitfalls that may cause code errors or fail to meet expectations. This article will introduce some of the most susceptible pitfalls for Python beginners and provide some solutions to help readers avoid these pitfalls.
Indentation error
Python uses indentation to represent code blocks, rather than using braces like other programming languages. Therefore, indentation errors are one of the common problems newbies encounter. In Python, statements within the same code block must have the same indentation level.
if True:
print("Indented incorrectly!") # This line of code is indented error✨ Solution: Enable indent display in the editor and always maintain a consistent indentation style, usually using four spaces.
Forgot to introduce modules
Modules in Python are reusable units of code, but they must be introduced before using functions or variables in modules. If you forget to introduce the module, the Python interpreter will not recognize the contents in the module.
# No math module was introducedresult = (25)
✨ Solution: Introduce all modules to use at the beginning of the code, or use the full module name to call functions or variables.
Use undefined variables
Before using variables, they must be defined. If an undefined variable is used, the Python interpreter raises a NameError exception.
print(x) # x Undefined
✨ Solution: Make sure to define before using variables and avoid undefined variables.
Don't understand the scope of variables
Variable scopes in Python are divided into global scope and local scope. Variables defined inside a function usually have a local scope, while variables defined outside a function have a global scope. When using global variables inside a function, you need to use the global keyword declaration.
x = 10
def increment():
x += 1 # If you try to modify the global variable x, an UnboundLocalError exception will be raised
increment()
✨ Solution: Understand variable scope rules in Python and pay attention to handling global variables correctly inside functions.
String formatting error
In Python, there are many ways to format strings, such as using the % operator, the () method, or the f-string. If an error occurs while formatting a string, it may cause the program to crash or output incorrect results.
name = "Alice"
age = 30
print("Her name is %s and she is %d years old" % name, age) # Format error✨ Solution: Be familiar with different string formatting methods and make sure that the formatted string matches the number and type of parameters provided.
Use keywords indiscriminately
There are many reserved keywords in Python that have specific meanings and are used in the syntax and structure of programming languages. Newbie may misuse these keywords, causing the code to go wrong or fail to function properly.
Example:
# Try to use keywords as variable names True = False None = 10
✨ Solution: Avoid using reserved keywords as variable names or identifiers. If you are not sure whether a name is a keyword, you can view it through the following code
import keyword #Introduce keyword module print() # Print keyword list
Extra symbols
When writing Python code, extra symbols may cause syntax errors or code behavior is not as expected. These symbols include unnecessary spaces, brackets, commas, etc.
Example:
# Unnecessary spacesx = 10 + 5 # Extra commasnumbers = [1, 2, 3,] # Mismatch bracketsresult = (5 + 3 print(result)
✨ Solution: Double-check the code, remove the redundant symbols, and make sure the symbols are used in compliance with Python's syntax specifications. It is recommended to use the automatic formatting feature provided by the code editor or the IDE to help eliminate unnecessary symbols.
Concurrent programming misunderstanding
Multithreaded/multi-process synchronization problemThe synchronization mechanisms such as locks and semaphores are not properly handled, resulting in data competition or deadlock.
Asynchronous IO operationInadequate understanding of the asynchronous programming model, such as improper use of the asyncio library, may also cause unpredictable problems.
Summarize
This is the article about the most easy pitfalls for Python beginners and guides to avoid pitfalls. For more related content for Python beginners, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!