1.Dates in Python

Dates in Python

Python has a built-in module called datetime to work with dates and times. Here’s an overview of how to handle dates in Python.

Creating Date Objects

To create a date, we can use the datetime module. Here’s how you can create date objects in Python:

import datetime

# Create a date object
x = datetime.datetime(2020, 5, 17)

print(x)

The strftime() Method

The strftime() method formats date objects into readable strings. Here are some common date formatting codes:

• %Y: Full year with century (e.g., 2024)
• %m: Month as a zero-padded decimal number (01-12)
• %d: Day of the month as a zero-padded decimal number (01-31)
• %H: Hour (00-23)
• %M: Minute (00-59)
• %S: Second (00-59)

Example of using strftime() method:

import datetime

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

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

print("Formatted date and time:", formatted_date)

Additional Examples

Getting the Current Date and Time

import datetime

now = datetime.datetime.now()

print("Current date and time:", now)

Extracting Year, Month, Day, Hour, Minute, and Second

import datetime

now = datetime.datetime.now()

print("Year:", now.year)
print("Month:", now.month)
print("Day:", now.day)
print("Hour:", now.hour)
print("Minute:", now.minute)
print("Second:", now.second)

Parsing Strings into Date Objects

import datetime

date_string = "2024-05-18"
date_object = datetime.datetime.strptime(date_string, "%Y-%m-%d")

print("Date object:", date_object)

Importing the datetime Module

To use dates in Python, you need to import the datetime module. This module provides classes for manipulating dates and times.

import datetime

Creating a Date Object

You can create a date object using the datetime class within the datetime module. Here’s an example of creating a date object for the current date and time:

import datetime

x = datetime.datetime.now()
print(x)

import datetime

x = datetime.datetime.now()
print(x)

This will output the current date and time.

Accessing Attributes of the Date Object

The datetime module allows you to access various attributes of the date object, such as year, month, day, hour, minute, and second.

import datetime

x = datetime.datetime.now()
print(x.year)
print(x.month)
print(x.day)
print(x.hour)
print(x.minute)
print(x.second)

Formatting Dates

The strftime() method allows you to format dates into readable strings. Here are some examples of how to format dates:

import datetime

x = datetime.datetime.now()

# Format the date and time
formatted_date = x.strftime("%Y-%m-%d %H:%M:%S")
print("Formatted date and time:", formatted_date)

Common date formatting codes:

• %Y: Full year with century (e.g., 2024)
• %m: Month as a zero-padded decimal number (01-12)
• %d: Day of the month as a zero-padded decimal number (01-31)
• %H: Hour (00-23)
• %M: Minute (00-59)
• %S: Second (00-59)

Example Code

Here is a full example showing how to import the datetime module, create a date object, and access its attributes:

import datetime

# Create a date object
x = datetime.datetime.now()

# Print the date object
print(x)

# Access and print individual attributes
print("Year:", x.year)
print("Month:", x.month)
print("Day:", x.day)
print("Hour:", x.hour)
print("Minute:", x.minute)
print("Second:", x.second)

# Format the date and print it
formatted_date = x.strftime("%Y-%m-%d %H:%M:%S")
print("Formatted date and time:", formatted_date)

2.Math in Python

Math in Python

Python provides various built-in math functions and a dedicated module named math to perform mathematical operations. Here’s an overview of math in Python.

Built-in Math Functions

Python offers several built-in functions that are useful for mathematical operations:

• abs(): Returns the absolute value of a number.
• max(): Returns the maximum of a set of numbers.
• min(): Returns the minimum of a set of numbers.
• pow(): Returns the value of x to the power of y.
• round(): Rounds a number to a specified number of decimal places.

Example:

print(abs(-7))        # Output: 7
print(max(3, 5, 1))   # Output: 5
print(min(3, 5, 1))   # Output: 1
print(pow(2, 3))      # Output: 8
print(round(5.567, 2)) # Output: 5.57

The math Module

The math module provides more advanced mathematical functions and constants. To use this module, you need to import it first:

import math

Some of the key functions and constants in the math module include:

• math.sqrt(x): Returns the square root of x.
• math.factorial(x): Returns the factorial of x.
• math.sin(x): Returns the sine of x (x is in radians).
• math.cos(x): Returns the cosine of x (x is in radians).
• math.pi: The mathematical constant π (pi).
• math.e: The mathematical constant e (base of natural logarithm).

Example:

import math

print(math.sqrt(16))      # Output: 4.0
print(math.factorial(5))  # Output: 120
print(math.sin(math.pi / 2)) # Output: 1.0
print(math.cos(math.pi))  # Output: -1.0
print(math.pi)            # Output: 3.141592653589793
print(math.e)             # Output: 2.718281828459045

Example Code

Here is a complete example showing the usage of built-in math functions and the math module:

import math

# Built-in functions
absolute_value = abs(-10)
maximum_value = max(10, 20, 30)
minimum_value = min(10, 20, 30)
power_value = pow(2, 3)
rounded_value = round(5.678, 2)

print("Absolute Value:", absolute_value)
print("Maximum Value:", maximum_value)
print("Minimum Value:", minimum_value)
print("Power Value:", power_value)
print("Rounded Value:", rounded_value)

# Math module functions
square_root = math.sqrt(25)
factorial_value = math.factorial(5)
sine_value = math.sin(math.pi / 2)
cosine_value = math.cos(math.pi)
pi_value = math.pi
e_value = math.e

print("Square Root:", square_root)
print("Factorial:", factorial_value)
print("Sine Value:", sine_value)
print("Cosine Value:", cosine_value)
print("Pi Value:", pi_value)
print("e Value:", e_value)