Python datetime

The datetime module in Python provides classes to work with dates and times. In this tutorial, we'll cover some of the most commonly used classes and methods in the datetime module.

datetime.date class:

The date class represents a date (year, month, and day). Here's how to create a date object and access its attributes:

from datetime import date

# Create a date object
d = date(2023, 5, 1)

# Access date attributes
print(d.year)  # Output: 2023
print(d.month)  # Output: 5
print(d.day)  # Output: 1

To get the current date, use the date.today() method:

from datetime import date

# Get the current date
current_date = date.today()
print(current_date)

datetime.time class:

The time class represents a time of day (hour, minute, second, microsecond). Here's how to create a time object and access its attributes:

from datetime import time

# Create a time object
t = time(14, 30, 45)

# Access time attributes
print(t.hour)  # Output: 14
print(t.minute)  # Output: 30
print(t.second)  # Output: 45

datetime.datetime class:

The datetime class represents both date and time. Here's how to create a datetime object and access its attributes:

from datetime import datetime

# Create a datetime object
dt = datetime(2023, 5, 1, 14, 30, 45)

# Access datetime attributes
print(dt.year)  # Output: 2023
print(dt.month)  # Output: 5
print(dt.day)  # Output: 1
print(dt.hour)  # Output: 14
print(dt.minute)  # Output: 30
print(dt.second)  # Output: 45

To get the current date and time, use the datetime.now() method:

from datetime import datetime

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

datetime.timedelta class:

The timedelta class represents a duration or difference between two dates or times. Here's how to create a timedelta object and perform arithmetic operations with dates and times:

from datetime import datetime, timedelta

# Create datetime objects
dt1 = datetime(2023, 5, 1, 14, 30, 45)
dt2 = datetime(2023, 5, 10, 16, 45, 30)

# Calculate the difference between two datetimes
diff = dt2 - dt1
print(diff)  # Output: 9 days, 2:14:45

# Add a duration to a datetime
duration = timedelta(days=7, hours=3)
new_dt = dt1 + duration
print(new_dt)  # Output: 2023-05-08 17:30:45

Working with dates in Python using datetime:
- Description: The datetime module provides classes for working with dates and times in Python.
- Code:
```
from datetime import datetime

# Current date and time
current_datetime = datetime.now()
```
Creating datetime objects in Python:
- Description: datetime objects can be created by specifying the year, month, day, hour, minute, and second.
- Code:
```
from datetime import datetime

# Creating a datetime object
specific_datetime = datetime(2023, 1, 15, 12, 30, 0)
```

Formatting and parsing dates with datetime in Python:

Description: strftime is used to format datetime objects into strings, and strptime is used for parsing strings into datetime objects.
Code:

from datetime import datetime

# Formatting datetime
formatted_date = current_datetime.strftime('%Y-%m-%d %H:%M:%S')

# Parsing string to datetime
parsed_datetime = datetime.strptime('2023-01-15 12:30:00', '%Y-%m-%d %H:%M:%S')

Performing arithmetic operations with datetime objects:
- Description: datetime objects support arithmetic operations for calculating durations.
- Code:
```
from datetime import datetime, timedelta

# Adding days to a datetime object
future_date = current_datetime + timedelta(days=7)
```

Dealing with time zones in Python datetime:

Description: Use the pytz library to work with time zones in datetime.
Code:

from datetime import datetime
import pytz

# Creating a datetime object with time zone
tz = pytz.timezone('America/New_York')
localized_datetime = datetime.now(tz)

Handling timedelta for date and time differences in Python:
- Description: timedelta represents the difference between two dates or times.
- Code:
```
from datetime import datetime, timedelta

# Creating a timedelta object
time_difference = future_date - current_datetime
```

Converting between datetime and string in Python:

Description: Convert datetime objects to strings and vice versa.
Code:

from datetime import datetime

# Converting datetime to string
date_string = current_datetime.strftime('%Y-%m-%d %H:%M:%S')

# Converting string to datetime
converted_datetime = datetime.strptime(date_string, '%Y-%m-%d %H:%M:%S')

Using datetime with file I/O in Python:

Description: Store and retrieve datetime objects in/from files.
Code:

from datetime import datetime

# Writing datetime to a file
with open('timestamp.txt', 'w') as file:
    file.write(current_datetime.strftime('%Y-%m-%d %H:%M:%S'))

# Reading datetime from a file
with open('timestamp.txt', 'r') as file:
    stored_datetime = datetime.strptime(file.read(), '%Y-%m-%d %H:%M:%S')