Python Dates

Understanding Python Datetime Module （了解Python Datetime模块）

Python’s datetime module offers a suite of classes for working with dates and times, including date, time, datetime, timedelta, and tzinfo. These classes provide a powerful and flexible way to store, manipulate, and format dates and times in Python. （Python的datetime模块提供了一套用于处理日期和时间的类，包括date、time、datetime、timedelta和tzinfo。这些类提供了一种强大而灵活的方式来存储、操作和格式化Python中的日期和时间。）

date Class #

date Class

The date class represents a date (year, month, day) and offers methods to perform various date-related operations such as retrieving the current date, formatting dates for output, and performing date arithmetic. （Date类表示日期（年、月、日） ，并提供执行各种日期相关操作的方法，例如检索当前日期、为输出设置日期格式以及执行日期算术。）

time Class #

time Class （时间类）

The time class represents the time of day and offers methods to perform operations such as formatting times for output and performing time arithmetic. （时间类表示一天中的时间，并提供执行输出格式化时间和执行时间算术等操作的方法。）

datetime Class #

datetime Class （datetime类）

The datetime class combines the features of the date and time classes, providing methods to work with both dates and times in a single object. （Datetime类结合了日期和时间类的功能，提供了在单个对象中同时处理日期和时间的方法。）

timedelta Class #

timedelta Class （timedelta类）

The timedelta class represents a duration or the difference between two dates or times, enabling you to perform arithmetic with dates and times by adding or subtracting timedelta objects. （Timedelta类表示持续时间或两个日期或时间之间的差异，使您能够通过添加或减去timedelta对象来执行日期和时间的算术。）

tzinfo Class #

tzinfo Class （tzinfo类）

The tzinfo class allows you to store time zone information and to perform time zone conversions. （Tzinfo类允许您存储时区信息并执行时区转换。）

Formatting Dates and Times for Output #

Formatting Dates and Times for Output （设置输出日期和时间格式）

The strftime method of the date, time, and datetime classes lets you format dates and times for output. The method takes a format string as an argument and returns a string representation of the date or time in the specified format. （DATE、TIME和DATETIME类的strftime方法允许您设置输出日期和时间的格式。该方法将格式字符串作为参数，并以指定格式返回日期或时间的字符串表示。）

Parsing Dates and Times from Strings #

Parsing Dates and Times from Strings （从字符串解析日期和时间）

The strptime method of the date, time, and datetime classes allows you to parse dates and times from strings. The method takes a format string as an argument and returns a datetime object. （DATE、TIME和DATETIME类的strptime方法允许您从字符串解析日期和时间。该方法将格式字符串作为参数，并返回datetime对象。）

Performing Date Arithmetic #

Performing Date Arithmetic （执行日期算术）

You can perform arithmetic with dates and times by adding or subtracting timedelta objects. This makes it easy to calculate future or past dates and times. （您可以通过添加或减去timedelta对象来执行日期和时间的算术。这样可以轻松计算未来或过去的日期和时间。）

Time Zone Conversions #

Time Zone Conversions （时区转换）

The pytz library offers time zone support for Python, simplifying time zone conversions. （Pytz库为Python提供了时区支持，简化了时区转换。）

Here are some examples to help you get started with the datetime module in Python. （以下是一些示例，可帮助您开始使用Python中的datetime模块。）

Example 1: Formatting a Date and Time for Output #

Example 1: Formatting a Date and Time for Output

import datetime

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

# Format the date and time for output
output = now.strftime("%Y-%m-%d %H:%M:%S")

print(output)

Example 2: Parsing a Date and Time from a String #

Example 2: Parsing a Date and Time from a String

import datetime

# Define a date and time string
date_string = "2022-01-01 12:00:00"

# Parse the date and time string
parsed_datetime = datetime.datetime.strptime(date_string, "%Y-%m-%d %H:%M:%S")

print(parsed_datetime)

Example 3: Performing Date Arithmetic #

Example 3: Performing Date Arithmetic

import datetime

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

# Calculate the date and time one week from now
one_week_from_now = now + datetime.timedelta(weeks=1)

print(one_week_from_now)

Example 4: Time Zone Conversions #

Example 4: Time Zone Conversions

import datetime
import pytz

# Define a time zone
eastern = pytz.timezone("US/Eastern")

# Get the current date and time in the Eastern time zone
now_eastern = datetime.datetime.now(eastern)

# Convert the date and time to the UTC time zone
now_utc = now_eastern.astimezone(pytz.utc)

print(now_eastern)
print(now_utc)

Example 5: Formatting a Timestamp for Output #

Example 5: Formatting a Timestamp for Output

import datetime

# Get the current timestamp
timestamp = datetime.datetime.timestamp(datetime.datetime.now())

# Format the timestamp for output
output = datetime.datetime.fromtimestamp(timestamp).strftime("%Y-%m-%d %H:%M:%S")

print(output)

As you can see, the datetime module in Python provides a range of powerful and flexible tools for working with dates and times. Whether you need to format dates and times for output, parse dates and times from strings, perform date arithmetic, or perform time zone conversions, the datetime module has you covered. With the help of this guide, you’ll be able to harness the full power of the datetime module to perform a wide range of date and time-related tasks in Python. （如您所见， Python中的datetime模块提供了一系列功能强大且灵活的工具来处理日期和时间。无论您需要为输出设置日期和时间格式、从字符串中解析日期和时间、执行日期算术还是执行时区转换， datetime模块都能满足您的需求。在本指南的帮助下，您将能够利用datetime模块的全部功能在Python中执行各种与日期和时间相关的任务。）