Master Python Functions and Time Utilities: From Basics to Real-World Code

1. Function Overview

In Python, a function groups specific code into a reusable unit, allowing you to encapsulate functionality and call it whenever needed.

2. Function Definition and Invocation

Defining a function creates a tool you can later use; calling the function executes the code inside.

def test():
    print('----嘻嘻----')
    print('----这是我的第一个函数----')

Calling the function runs the defined code.

# Define a function

def test():
    print('----嘻嘻----')
    print('----这是我的第一个函数----')

# Call the function
test()

Result:

Time Functions

Time-related functions are useful for debugging and logging.

1. Get current timestamp: time.time()

import time  # import time module
currentTime = time.time()
print("当前时间戳为:", currentTime)

2. Get local time tuple: time.localtime(time.time())

import time
localtime = time.localtime(time.time())
print("本地时间为 :", localtime)

import time
localtime = time.asctime(time.localtime(time.time()))
print("本地时间为 :", localtime)

Extended (datetime module)

1. Date formatting: datetime → string

import datetime
now = datetime.datetime.now()
now.strftime('%Y-%m-%d %H:%M:%S')

2. String → datetime

import datetime
t_str = '2019-04-07 16:11:21'
d = datetime.datetime.strptime(t_str, '%Y-%m-%d %H:%M:%S')
print(d)

3. Date comparison using timedelta

The timedelta class represents a time interval and supports arithmetic operations.

import datetime
datetime.timedelta(days=0, seconds=0, microseconds=0, milliseconds=0, minutes=0, hours=0, weeks=0)

All parameters default to 0 and can be int or float.

import datetime
year = datetime.timedelta(days=365)
t_years = year * 10
new_years = t_years - year
print(t_years)
print(new_years)

Date, time and datetime classes also support addition/subtraction with timedelta.

datetime1 = datetime2 + timedelta
timedelta = datetime1 - datetime2

Calendar Functions

import calendar
dar = calendar.month(2016, 8)
print("2016年8月份的日历:")
print(dar)

Random Number Functions

import random
a = random.uniform(1, 5)
print("a =", a)

b = random.randint(10, 50)
print("b =", b)

c = random.randrange(0, 51, 2)
print("c =", c)

3. Summary

The article thoroughly explains Python function definition and invocation, introduces common time‑related functions from the time, datetime, calendar, and random modules, and provides runnable code snippets and output images to help readers practice and master these essential tools.