每个 Python 开发人员需要掌握的 5 个基本内置模块

# Import the sys module
import sys


# Get the Python version
python_version = sys.version
print("Python version:", python_version)

# Get the platform information
platform = sys.platform
print("Platform information:", platform)

# Get the Python path
python_path = sys.path
print("Python path:", python_path)

# Access command-line arguments
arguments = sys.argv

# Print the command-line arguments
print("Command-line arguments:", arguments)

# Get the first argument passed in
first_argument = sys.argv[1] if len(sys.argv) > 1 else None
print("First argument passed in:", first_argument)

# Terminate the program with a specific exit code
exit_code = 0  # Example exit code
sys.exit(exit_code)  # Terminate the program with the specified exit code

• os模块： 使用os模块，我们可以执行与操作系统相关的各种操作。它就像一个方便的工具箱，用于管理文件、目录和检查它们是否存在。

# Import the os module
import os

# Get the current working directory
current_directory = os.getcwd()

# List files and directories in a directory
directory_path = "/path/to/directory"
directory_contents = os.listdir(directory_path)

# Check if a file or directory exists
path = "/path/to/file_or_directory"
exists = os.path.exists(path)

# Get information about a file
file_info = os.stat(path)

# Create a directory
os.mkdir("new_directory")

# Rename a file
os.rename("old_file.txt", "new_file.txt")

# Remove a file
os.remove("file_to_remove.txt")

# Change current working directory
os.chdir("/new/directory/path")

• math模块：将数学模块视为 Python 中值得信赖的计算器。它包含用于执行数学运算的函数，例如平方根、三角函数和四舍五入数。

# Import the math module
import math

# Perform basic mathematical operations
result_sqrt = math.sqrt(25)  # Square root of 25
result_pow = math.pow(2, 3)   # 2 raised to the power of 3
result_abs = math.abs(-5)     # Absolute value of -5

# Calculate trigonometric functions
sine_value = math.sin(math.pi / 2)  # Sine of π/2 (90 degrees)
cosine_value = math.cos(math.pi)    # Cosine of π (180 degrees)
tangent_value = math.tan(math.pi/4) # Tangent of π/4 (45 degrees)

# Round numbers to the nearest integer
rounded_number_floor = math.floor(3.6)  # Rounds down to 3
rounded_number_ceil = math.ceil(3.2)    # Rounds up to 4
rounded_number_round = round(3.5)        # Rounds to the nearest integer (4)

# Calculate logarithms
log_value = math.log(10, 2)  # Logarithm of 10 to the base 2

# Calculate factorial
factorial_value = math.factorial(5)  # Factorial of 5 (5!)

# Convert angles between degrees and radians
degrees_to_radians = math.radians(90)  # Convert 90 degrees to radians
radians_to_degrees = math.degrees(math.pi / 2)  # Convert π/2 radians to degrees

• random模块：它就像一顶魔术帽，可以拉出随机数或打乱列表，为我们的程序增添一点不可预测性。

# Import the random module
import random

# Generate random integers within a range
random_number = random.randint(1, 10)  # Generates a random integer between 1 and 10

# Shuffle a list
my_list = [1, 2, 3, 4, 5]
random.shuffle(my_list)  # Shuffles the list randomly
print("Shuffled List:", my_list)

# Generate a random float between 0 and 1
random_float = random.random()  # Generates a random float between 0 and 1
print("Random Float:", random_float)

# Choose a random element from a sequence
my_sequence = ["apple", "banana", "orange", "grape"]
random_element = random.choice(my_sequence)  # Chooses a random element from the sequence
print("Random Element:", random_element)

# Generate a random sample from a population
sample = random.sample(range(1, 101), 5)  # Generate 5 unique random numbers from 1 to 100
print("Random Sample:", sample)

# Randomly select an element with replacement
random_element_with_replacement = random.choices(["A", "B", "C", "D"], k=3)  # Select 3 elements with replacement
print("Random Element with Replacement:", random_element_with_replacement)

# Set the random seed for reproducibility
random.seed(1234)  # Set the random seed to 1234

print(random.randint(1, 100))  # Output: 17
print(random.randint(1, 100))  # Output: 72
print(random.randint(1, 100))  # Output: 97

# Resetting the seed to the same value will produce the same sequence of random numbers
random.seed(1234)

print(random.randint(1, 100))  # Output: 17
print(random.randint(1, 100))  # Output: 72
print(random.randint(1, 100))  # Output: 97

• datatime模块： 是否需要在代码中使用日期和时间？这就是 datetime 模块派上用场的地方。它就像一个日历，可以帮助我们毫不费力地创建、格式化和操作日期和时间。

# Import the datetime module
import datetime

# Get the current date and time
current_datetime = datetime.datetime.now()

# Format a datetime object as a string
formatted_date = current_datetime.strftime("%Y-%m-%d %H:%M:%S")  # Format as YYYY-MM-DD HH:MM:SS
print("Formatted Date:", formatted_date)

# Create a datetime object from a string
date_string = "2024-05-08"
converted_date = datetime.datetime.strptime(date_string, "%Y-%m-%d")

# Calculate the difference between two dates
date1 = datetime.datetime(2024, 5, 8)
date2 = datetime.datetime(2024, 5, 10)
date_difference = date2 - date1  # Difference between date2 and date1
print("Difference between two dates:", date_difference)

# Get the current date
current_date = datetime.date.today()
print(current_date.strftime("%Y-%m-%d"))  # Print the current date in the format YYYY-MM-DD

# Calculate the difference between two datetime objects
timedelta = datetime.timedelta(days=7)
future_date = current_date + timedelta  # Date 7 days from now
print("Future Date (7 days from now):", future_date)

# Get the day of the week
day_of_week = current_date.strftime("%A")  # Full name of the day (e.g., Monday)