Python Tutorial for Beginners to Expert in 30 Days
What is Python:
Python is an interpreted, object-oriented, high-level programming language. It was created by Guido van Rossum and released in 1991. It is easy to learn and efficient with high-level data structures. Python codes are much shorter when compare to C, C++, Java.
Application of Pythons
Web Development
Scientific & Numeric ( Data Science, Machine Learning, AI)
Network Programming
Software & Game Development
How to Install Python?
We need to install python to get started. You can download the latest version of python from https://www.python.org/downloads/.
You can download for windows, mac, Unix and Linux os
How to check Python Version:
You need to execute the below command to know about the version of python.
>>> python –version
Python has different syntax for version 2.7 and 3.7. In this tutorial, we are using python 3.7 version.
Python First Program
I love the first program in python. Use Print function with curly braces to with quotes text to print hello world.
Code:
# This if First Python Program
print(‘Hello, world!’)
- Python Get Started
- Python Variables and Data Types
- Python Identifiers and Reserved Words
- Python Comments
- Python Operators
- Python Casting
- Python Strings
- Python Conditional Statements
- Python Functions
- Python For loops
- Python Arrays
- Python Lists
- Python List Comprehension
- Python Dictionaries
- Python Sets
- Python Modules
- Python Input/output
- Python Errors and Exceptions
- Python OOPs
- Python Regular Expressions
- Python Socket Programming
- Migrate from python 2 to Python 3
- Python In Built Functions
- Python Iterators
- Python Modules and Import
- Python File Handling
- Python and MySQL
- Python Programs
- Python fibonacci Number program
- Python Abs Program
- Python Leap Year Program
- Python Factorial Program
- Python Prime Number Program
- Python Even or Add Number Program
- Python Positive or Negative Number Program
- Python Simple Calculator Program
- Python Program to Convert Decimals
- Python Program to celsius to fahrenhei
- Python lambda Function Programs
- Python mean,median and mode Program
- Python Random Number Program
- Python Math Functions with Programs
- Python statistics with Programs
- Python round Function
- Python Range Function
- Python Min() and Max() Functions
- Python Zip() Function
- Python program to calculate area of traingle
Python Get Started:
We need to install python to get started. You can download the latest version of python from https://www.python.org/downloads/.
You can download for windows, mac, Unix and Linux os
How to check Python Version:
You need to execute the below command to know about the version of python.
>>> python –version
Python has different syntax for version 2.7 and 3.7. In this tutorial, we are using python 3.7 version.
Python First Program
I love the first program in python. Use Print function with curly braces to with quotes text to print hello world.
Code:
# This if First Python Program
print(‘Hello, world!’)
In Python, we can write and execute code in two modes. One is Interactive and second one is Script Mode.
Interactive Mode Programming:
You have to open command prompt then type python to log in interpreter
C:/>python
Python version: 3.63
>>> print “Hello, World!”
Output: Hello, World!
Server Side Mode Programming:
When you run a program from the interpreter, It won’t exist for a long time. It will delete code after exit from it. You have to save file with .py file extension to run.
$python first.py
Output: Hello, World!
Python Variable:
Variables are used to store values. In python, there is no explicit declaration for variables. If you pass an integer value to a variable it will automatically create integer variable same with other formats also.
Example:
a= 1
b=2.5
c="test"
print(a)
print(b)
print(c)
print(type(a))
print(type(b))
print(type(c))
Output:
1
2.5
test
<class ‘int’>
<class ‘float’>
<class ‘str’>
Python Data Types:
In python we have mainly 5 data types
• Numbers
• Strings
• Lists
• Tuples
• Dictionaries
Python Numbers:
We have 3 types of numbers in python, if we assign value to them, if will convert to that datatype automatically.
1. Integer
2. Float
3. Complex
Python Integers:
Integer is a Number. You can define Positive, Negative Integer numbers with decimals
Example:
a= 100
print(a)
print(type(a))
a= -100
print(a)
print(type(a))
Output:
100
<class ‘int’>
-100
<class ‘int’>
Python Float:
Float number is a fractional value. You can pass positive and negative numbers.
Example:
a= 10.555555
print(a)
print(type(a))
a= -10.5758585
print(a)
print(type(a))
Output:
10.555555
<class ‘float’>
-10.5758585
<class ‘float’>
Python Complex Numbers:
Complex is a number with equation a+bj . a and b are the real values of graph. J is an imaginary number. We can represent with positive and negative numbers.
Example:
c= 10+5j
print(c)
print(type(c))
c= -10+5j
print(c)
print(type(c))
Output:
(10+5j)
<class ‘complex’>
(-10+5j)
<class ‘complex’>
Python Strings:
String is a representation of continuous characters. In Python, You can define by using single quotes and double quotes. You can find substring by using slice operator [:]. The string index is starting from 0. You can concatenate string by using + operator and * used to repeat the strings.
Example:
Str = 'I love python'
print(Str)
print(Str[0])
print(Str)
print(Str[:6])
print(Str[6:])
print(str+str)
print(Str+' '+ Str)
print(Str *2)
Output:
I love python
I
I love python
I love
Python
Python
I love python I love python
I love pythonI love python
Python Lists:
Python list is versatile sequence data type, you can store integer, float, character in a single list. Same like arrays it index is also zero. You can use slice [:] operator to call subsets. You can concatenate lists by using + operator and repeat by using * operator.
Example:
Str = ['I', 'love', 'python', 'version','3.6']
print(Str)
print(Str[0])
print(Str)
print(Str[:2])
print(Str[2:])
print(Str+Str)
print(Str * 2)
Output:
[‘I’, ‘love’, ‘python’, ‘version’, ‘3.6’]
I
[‘I’, ‘love’, ‘python’, ‘version’, ‘3.6’]
[‘I’, ‘love’]
[‘python’, ‘version’, ‘3.6’]
[‘I’, ‘love’, ‘python’, ‘version’, ‘3.6’, ‘I’, ‘love’, ‘python’, ‘version’, ‘3.6’]
[‘I’, ‘love’, ‘python’, ‘version’, ‘3.6’, ‘I’, ‘love’, ‘python’, ‘version’, ‘3.6’]
Python Tuples:
Python tuples are same like lists. The only difference is it is read only lists. It can’t update. You can define by using Parenthesis operator ()
Example:
Str = ('I', 'love', 'python', 'version','3.6')
print(Str)
print(Str[0])
print(Str)
print(Str[:2])
print(Str[2:])
print(Str+Str)
print(Str * 2)
Output:
(‘I’, ‘love’, ‘python’, ‘version’, ‘3.6’)
I
(‘I’, ‘love’, ‘python’, ‘version’, ‘3.6’)
(‘I’, ‘love’)
(‘python’, ‘version’, ‘3.6’)
(‘I’, ‘love’, ‘python’, ‘version’, ‘3.6’, ‘I’, ‘love’, ‘python’, ‘version’, ‘3.6’)
(‘I’, ‘love’, ‘python’, ‘version’, ‘3.6’, ‘I’, ‘love’, ‘python’, ‘version’, ‘3.6’)
If you forcefully try to change values in lists it will produce the following error
Example:
Str[0] =’test’
TypeError: ‘tuple’ object does not support item assignment
Python Dictionaries:
Python dictionaries are unordered data types which come with key and value pairs. We can call values by using keys. The keys can be numbers and strings. Dictionaries are defined by using {}.
Example:
Dictionary = {"name":"python", "version":"3.6"}
print(Dictionary)
print(Dictionary['name'])
print(Dictionary['version'])
Output:
{‘name’: ‘python’, ‘version’: ‘3.6’}
python
3.6
Python Identifiers :
An identifier is a name used to identify the variables, functions, classes, objects, and modules.
You don’t have to use special characters like “@,$,%” in identifiers.
Python Reserved words :
Python has a list of a reserved word for a specific task. We are not allowed those words as identifiers.
Here is the list of words:
1. and
2. exec
3. not
4. assert
5. finally
6. or
7. break
8. for
9. pass
10. class
11. from
12. print
13. continue
14. global
15. raise
16. def
17. if
18. return
19. del
20. import
21. try
22. elif
23. in
24. while
25. else
26. is
27. with
28. except
29. lambda
30. yield
31. true
32. false
33. None
Python Comments:
Single Line Comment:
If you want to comment a single line in python, you have to use # in starting of the sentence.
Example: #print("hello world")
Multiline Comment:
For multiline comments, you have to use triple quotes in starting and ending of the lines
Example: """a= 1 b=2 c=a+b print(c) """
Python Operators:
In C, C++ languages like python also have 7 types of operators
1. Arithmetic Operators
2. Comparison (Relational) Operators
3. Assignment Operators
4. Logical Operators
5. Bitwise Operators
6. Membership Operators
7. Identity Operators
1. Arithmetic Operators :
Arithmetic Operators are like addition, subtraction, division, multiplication, Modular, and Floor Division.
Example:
a= 5
b= 4
print('a+b =', a+b)
print('a-b =', a-b)
print('a*b =', a*b)
print('a/b =', a/b)
print('a%b =', a%b)
print('a//b =', a//b)
Output:
a+b = 9 a-b = 1 a*b = 20 a/b = 1.25 a%b = 1 a//b = 1
2. Comparison Operations:
Comparison Operators compare both sides of the values. It will produce true and false results. The operators ==,!=, >, <, <>, <=,>=.
Example:
a= 5 b= 4 print('a==b =', a==b) print('a!=b =', a!=b) print('a>b =', a>b) print('a<b =', a<b) print('a>=b =', a>=b) print('a<=b =', a<=b)
Output:
a==b = False a!=b = True a>b = True a<b = False a>=b = True a<=b = False
3. Assignment Operators:
These operators are used to assign values to variables. You can do arithmetic operations while assigning variables also.
Example:
a= 5
b= 4
c=0
print('C value', c)
c+=a
print('C value', c)
c*=a
print('C value', c)
c-=a
print('C value', c)
c/=a
print('C value', c)
c%=a
print('C value', c)
c//=a
print('C value', c)
c**=a
print('C value', c)
Output:
C value 0 C value 5 C value 25 C value 20 C value 4.0 C value 4.0 C value 0.0 C value 0.0
Python Logical Operators:
In python we have 3 logical operators are there. And, Or, Not – We can use these operators with multiple statement comparisons
And – If both the statements true it returns, true value
Or – if any one of the statement false it returns true value
Not – It is used to reverse the result with true to false or false to true
Example:
a= 5
b= 4
c=7
print('a>b and c>b =', a>b and c>b)
print('a>b or c>b =', a>b or c>b)
print('not(a>b or c>b) =', not(a>b and c>b))
Output:
a>b and c>b = True a>b or c>b = True not(a>b or c>b) = False
Python Identity Operators:
We have 2 identity operators in python. We can use them to compare variable values. If the value of variable is equal it returns true value, otherwise it returns false value.
Is – Returns true value if the both variables have same object
Is not – Returns true value if the both variables have not same object
Example 1:
a= 5
b= 4
print('a is b', a is b)
print('a is not b =', a is not b)
Output:
a is b False a is not b = True
Example 2:
a= 5
b= 5
print('a is b', a is b)
print('a is not b =', a is not b)
Output:
a is b True a is not b = False
Python Membership operators:
Python membership operators are used to test the variables are present in the sequences of tuples, lists, arrays and strings. We have 2 membership operators.
In – Returns true value, if the object present in sequence
Not in – Returns true value, if the object not present in sequence
Example 1:
a= 3
b= [2,3,5,8,9]
print('a in b', a in b)
print('a not in b =', a not in b)
Output:
a in b True a not in b = False
Example 2:
a= 4
b= [2,3,5,8,9]
print('a in b', a in b)
print('a not in b =', a not in b)
Output:
a in b False a not in b = True
Python Bitwise Operators:
In python we have 6 bitwise operators – &, |, ^, ~, >>, <<. It performed operation bit by bit between variables.
Example:
a= 5 b= 5 print('a & b =', a & b) print('a | b =', a | b) print('a ^ b =', a ^ b) print('a ~ b =', a ~ b) print('a<<b =', a<<b) print('a>>b =', a>>b)
Output:
a & b = 5 a | b = 5 a ^ b = 0 a ~ b = -6 a<<b = 160 a>>b = 0
Python casting :
The process of converting from one datatype to another is called type casting. In python, First we need to know what are the current datatypes and how we can do it.
We have 2 types of type casting
- Implicit type conversion
- Explicit type conversion
Implicit type conversion : This type of conversion of automatically happen by the python interpreter. This process doesn’t require any user actions. we will use type function to know the datatype of variable.
Example 1:
int_number = 1 float_number = 1.542 addition = int_number + float_number print("addition number", addition) print("final variable datatype", type(addition)) print("data type of integer variable after addition with float ", type(int_number))
Output:
addition number 2.542 final variable datatype <class 'float'> data type of integer variable after addition with float <class 'int'>
By Understanding above output, If we do adding with integer number and float number , The Output is float number. The datatype conversion is automatically happen.
Note :
If we are planning addition with sting to integer or float we will get error
Example 2:
int_number = 154 sting_number = "154" addition = int_number + sting_number print("addition number", addition) print("final variable datatype", type(addition))
Output:
TypeError: unsupported operand type(s) for +: 'int' and 'str'
Explicit Type Conversion:
In this conversion, we will convert datatypes to explicitly by using datatype function like int(), float() etc.
In example 2 we are facing the error, we will solve by using explicit type conversion
int_number = 154 sting_number = int("154") addition = int_number + sting_number print("addition number", addition) print("final variable datatype", type(addition)) print("data type of string variable after addition with integer ", type(sting_number))
Output:
addition number 308
final variable datatype <class ‘int’>
data type of string variable after addition with integer <class ‘int’>
Float Conversion:
float_number = 154.5 sting_number = float("154") addition = float_number + sting_number print("addition number", addition) print("final variable datatype", type(addition)) print("data type of string variable after addition with float number", type(sting_number))
Output:
addition number 308.5
final variable datatype <class ‘float’>
data type of string variable after addition with integer <class ‘float’>
Sting is a set of characters. you can define with single, double and tipple quotes in python. We have inbuilt string functions to make easy process.
Python String Methods:
a= "Hello python" print(a)
Output:
Hello python
#code
print(a[0])
Output:
H
slicing of string or subset of string
print("\nSlicing of string") print(a[0:5]) print(a[5:]) print(a[:-4])
Output:
Slicing of string Hello python Hello py
length of string
print("\nlength of string") print(len(a))
Output:
length of string 12
Capitalize all characters
print(a.upper())
Output:
HELLO PYTHON
Convert all characters to small characters
print(a.lower())
Output:
hello python
#Return a title cased version of the string
print(a.title())
Output:
Hello Python
Return true if there are only whitespace characters in the string
print(a.isspace())
Output:
False
#Return the number of non-overlapping occurrences of substring
print(a.count('H'))
Output: 1
#Return an encoded version of the string as a bytes object
print(a.encode(encoding="utf-32", errors="strict"))
Output:
b'\xff\xfe\x00\x00H\x00\x00\x00e\x00\x00\x00l\x00\x00\x00l\x00\x00\x00o\x00\x00\x00 \x00\x00\x00p\x00\x00\x00y\x00\x00\x00t\x00\x00\x00h\x00\x00\x00o\x00\x00\x00n\x00\x00\x00'
#Return True if the string ends with the specified suffix, otherwise return False
print(a.endswith('.'))
Output:
False
#Return true if all characters in the string are alphabetical
print(a.isalpha())
Output:
False
#Return a list of the words in the string, using sep as the delimiter string.
print(a.split(' '))
Output:
['Hello', 'python']
#Return True if string starts with the prefix, otherwise return False.
print(a.startswith('H'))
Output:
True
#Return True if string ends with the prefix, otherwise return False.
print(a.endswith('.'))
Output:
False
#Return the lowest index in the string where substring sub is found within the slice
it return ‘0’ if he string found and ‘-1’ not found
print(a.find('Hello'))
Output:
0
# the old sub string to new
print(a.replace('Hello','New'))
Output:
New python
#returns index value
print(a.index('python'))
Output:
6
# adding a sub string to main string
print(a.join('Hi '))
Output:
HHello pythoniHello python
Python For loops:
In python we will use for loops for iterative process. We can iterate strings, lists, tuples, dictionaries with sequence order.
Syntax:
for variable in sequence
body
Example :
#python for loop example program
values = [5,8,9,7,8,9,10]
# iterate over the list
for val in values:
print(val)
Output:
5 8 9 7 8 9
python for loop program to add 2 with list.
values = [5,8,9,7,8,9,10]
#addition all list values with 2
# iterate over the list
for val in values:
print(val+2)
Output:
7 10 11 9 10 11 12
For loop with range :
Range function: It is used to print the sequence numbers, it has start and stop function, By using this we can print specific range numbers.
Example:
print(list(range(10)))
Output:
print(list(range(2,10)))
Output:
Example:
for i in range(10):
print(i)
Output:
0 1 2 3 4 5 6 7 8 9
for i in range(2,10): print(i*2)
Output:
4 6 8 10 12 14 16 18
For loop with if function :
We can use if condition in for loop with range function. In this below example i am printing even numbers.
for i in range(0,10): if i % 2 == 0 : print('Even number :', i)
Output:
Even number : 0 Even number : 2 Even number : 4 Even number : 6 Even number : 8
For loop with if else :
We will use for loop with if else condition. Here i am providing the even and odd number example. First it iterates the value in then go with if condition if the condition is true it prints the even number . Then it will goes to else block it print odd number.
Example Program:
for i in range(0,10): if i % 2 == 0 : print('Even number :', i) else: print('Odd Number :', i)
Output:
Even number : 0 Odd Number : 1 Even number : 2 Odd Number : 3 Even number : 4 Odd Number : 5 Even number : 6 Odd Number : 7 Even number : 8 Odd Number : 9
Python lists:
Python lists are powerful data structures, we can define by using []. We can store numbers, strings, float numbers in this list. We can do append,insert, extend, pop, delete methods using lists.
First we need to learn how create a empty list, string list, float list then we can go further.
How to create a empty list:
We can create a list by using [] operator.
List = []
print("Blank list")
print(List)
Output:
Blank list []
How to create a list with values:
Here i am create a list with values and printing that list.
List = [1, 2, 4, 4, 3, 3, 3, 6, 5]
print("\nList with the use of Numbers: ")
print(List)
Output:
List with the use of Numbers: [1, 2, 4, 4, 3, 3, 3, 6, 5]
How to create a string list:
Here i am create a list with string values, by specifying string values with quotes and commas
#list with strings
List = ["Dog", "fish", "Cat"]
print("\nList containing with string values: ")
print(List)
Output:
List containing with string values: ['Dog', 'fish', 'Cat']
How to create a float list:
List = [1.5,2.5,3.5,7.8,9.5]
print("\nList containing with float values: ")
print(List)
Output:
List containing with float values: [1.5, 2.5, 3.5, 7.8, 9.5]
How to Create a Multi Variable List :
#mutli variable list
List = [1,2,'cat',3.5,7.8,9.5]
print("\nList containing with multitype values: ")
print(List)
Output:
List containing with multi-type values: [1, 2, 'cat', 3.5, 7.8, 9.5]
List Operations with Append, Pop, Delete, Extend etc.
If you want to change list data, we need to use list operations with desired inbuilt functions.
How to Add Elements to the list:
We can add elements to the list by using append(), extend() and insert functions.
List.append() function:
This function used to append a new value to the list.
Syntax: list.append(‘value’)
#program to understand append function in lists.
List =[1,2,3,4]
List.append(5)
print("\nList after appending value ")
print(List)
Output:
List after appending value [1, 2, 3, 4, 5]
List.append():
This function used to add a new value for specific index to the list.
Syntax: list.insert(position, value)
List =[1,2,3,4]
List.insert(2,5)
print("\nList appending value at starting of the list ")
print(List)
Output:
List appending value at starting of the list [1, 2, 5, 3, 4]
How to remove element from the list:
We can remove list elements by using pop() and remove() functions.
List.pop() function:
This function help to remove the last element from the list.
List =[1,2,3,4]
List.pop()
print("\nRemoving last element from list")
print(List)
Output:
Removing last element from list
[1, 2, 3]
List.remove():
list.remove() function helps to remove specific item from the list.
List =[1,2,3,4]
List.remove(2)
print("\nRemoving specific element from list")
print(List)
Output:
Removing specific element from list
[1, 3, 4]
#Example 2 on Remove list items
List =[1,2,3,4]
del List[0]
print("\nRemoving starting element from list")
print(List)
Output:
Removing starting element from list
[2,3,4]
How to delete all elements from list.
List.clear()
List.clear() function helps to delete all items from the list,
List =[1,2,3,4]
List.clear()
print("\nClear the list")
print(List)
Output:
Clear the list
[]
How to copy one list to another list ?
List.copy() function:
List.copy() function helps to create a new list by copying all elements from the old list.
del List
List = [1, 2, 4, 4, 3, 3, 3, 6, 5]
List2 = List.copy()
print("\nCopy the list 1 to list 2")
print(List2)
Output:
Copy the list 1 to list 2
[1, 2, 4, 4, 3, 3, 3, 6, 5]
How to count specific element from the list ?
List.count():
This function helps to count the specific element from the list.
List = [1, 2, 4, 4, 3, 3, 3, 6, 5]
Count = List.count(4)
print("\nCounting of number of times that values appears in the list")
print(Count)
Output:
Counting of number of times that values appears in the list
2
How to Check index of the list element:
List.index() Function:
list.index() function helps to find the element by using index.
List = [1, 2, 4, 4, 3, 3, 3, 6, 5]
index = List.index(4)
print("\nTo check Index value of value")
print(index)
Output:
To check Index value of value
2
How to Reverse the list elements:
List.reverse():
This function helps to reverse a list.
List = [1, 2, 4, 4, 3, 3, 3, 6, 5]
List.reverse()
print("\n Reverse of the list", List)
Output:
Reverse of the list
[5, 6, 3, 3, 3, 4, 4, 2, 1]
How to Sort List Elements :
List.sort() function:
This function help us to sort a list using ascending order and descending order.
List = [1, 2, 4, 4, 3, 3, 3, 6, 5]
print(List)
List.sort()
print("\n sorting of the list Ascending")
print(List)
List.sort(reverse=True)
print("\n sorting of the list Descending")
print(List)
Output:
sorting of the list Ascending [1, 2, 3, 3, 3, 4, 4, 5, 6] sorting of the list Descending [6, 5, 4, 4, 3, 3, 3, 2, 1]
List = [1, 2, 4, 4, 3, 3, 3, 6, 5]
print(List)
List2= [4,5,6]
List.extend(List2)
print("\n Extented list")
print(List)
Output:
Extented list
[1, 2, 4, 4, 3, 3, 3, 6, 5, 4, 5, 6]
Python List Comprehension:
In this tutorial, you will learn about python List Comprehension with Examples, You can use this List Comprehension for Data Science and machine learning developments.
Def : It’s a process of creating new lists by using old lists with condition statements
Syntax : [ expression for loop if conditionals]
List Comprehension Advantages :
- Less Code – single line statement.
- Fast code execution when compare to function and map functions
- Special uses cases in machine learning and data science projects
#python example programs on list comprehension
#Print odd and even numbers using list comprehensive method
list = [1,2,3,4,5,6,7,8,9,10]
even_numbers = [i for i in range(10) if(i%2==0) ]
print(even_numbers)
odd_numbers = [i for i in range(10) if(i%2!=0) ]
print(odd_numbers)
Output:
[0, 2, 4, 6, 8] [1, 3, 5, 7, 9]
#multiplication using list comprehension
multiplication = [5*i for i in list ]
print(multiplication)
Output:
[5, 10, 15, 20, 25, 30, 35, 40, 45, 50]
#functions in list comprehension
list = ["Hello Python", '3','Hi','5']
is_digit = [i for i in list if i.isdigit() ]
print(is_digit)
Output:
['3', '5']
list = ["Hello Python"] lower = [i.lower() for i in list] print(lower)
Output:
['hello python']
To Uppercase :
list = ["Hello Python"]
upper = [i.upper() for i in list]
print(upper)
Output:
['HELLO PYTHON']
Python Dictionaries:
It is unordered data structure with key and values. It defined with curley braces. We can create, edit, update and delete the values. We can store integer, float, strings and complex numbers.
How to Create a Empty Dictionary:
Create an empty dictionary with {} braces.
sample={}
print(sample)
Output:
{}
How to Create a Dictionary:
We can also create a dictionary with dict function in python with 3 ways. Here are those.
Example 1:
sample=dict({'a':10,'b':20})
print(sample)
Output:
{'a': 10, 'b': 20}
Example 2:
sample=dict(a=10,b=20)
print(sample)
Output:
{'a': 10, 'b': 20}
Example 3:
sample=dict([('a',10),('b',20)])
print(sample)
Output:
{'a': 10, 'b': 20}
How to Create of dictionary with Integer numbers:
We can create integer dictionaries by simply passing integer values to it.
int_dic={'a':10,'b':20,'c':30,'d':40}
print(int_dic)
Output:
{'a': 10, 'b': 20, 'c': 30, 'd': 40}
How to Create of dictionary with Float numbers:
We can create float dictionaries by simply passing float values to it.
float_dic={'a':10.5,'b':20.6,'c':30,'d':40}
print(float _dic)
Output:
{'a': 10.5, 'b': 20.6, 'c': 30, 'd': 40}
Mixed Datatypes Dictionary:
We can create dictionary with float, integer and strings.
Example Program code:
student={'age':20,'sex':'male','height':6.5}
print(student)
Output:
{'age': 20, 'sex': 'male', 'height': 6.5}
Nested dictionary:
We can create a nested dictionary a dictionary with in the dictionary.
nested = {'a':{'age': 20, 'sex': 'male', 'height': 6.5},
'b': {'age': 21, 'sex': 'male', 'height': 6.5} }
print(nested)
print(nested['b']['age'])
Output:
{'a': {'age': 20, 'sex': 'male', 'height': 6.5}, 'b': {'age': 21, 'sex': 'male', 'height': 6.5}} 21
How to accessing elements from dictionary:
We can access elements from dictionaries by using key for value.
Example Program code:
student={'age':20,'sex':'male','height':6.5}
print(student['sex'])
Output:
Male
How to add elements to dictionary:
We can add easily elements to dictionary by specifying key and value.
Example Program code:
student={'age':20,'sex':'male','height':6.5}
print(student)
student['salary'] =20000
print(student)
Output:
{'age': 20, 'sex': 'male', 'height': 6.5} {'age': 20, 'sex': 'male', 'height': 6.5, 'salary': 20000}
How to edit or Update elements to dictionary:
We can edit or update the values same like adding values with specifying key and values.
Example Program code:
student={'age':20,'sex':'male','height':6.5}
print(student)
student['age'] =21
print(student)
Output:
{'age': 20, 'sex': 'male', 'height': 6.5} {'age': 21, 'sex': 'male', 'height': 6.5}
How to delete elements from dictionary
We can delete elements from dictionaries using del command or pop .
Example program code:
student={'age':20,'sex':'male','height':6.5}
print(student)
del student['age']
print(student)
Output:
{'age': 20, 'sex': 'male', 'height': 6.5} {'sex': 'male', 'height': 6.5}
By using pop function
We can delete dictionary elements by using pop. We can call with below syntax
Syntax: dictionary. pop(indexvalue)
Example program code:
student={'age':20,'sex':'male','height':6.5}
print(student)
student.pop('sex')
print(student)
Output:
{'age': 20, 'sex': 'male', 'height': 6.5} {'age': 20, 'height': 6.5}
By using popitem function.
This function automatically removes the last item from the dictionary.
Syntax: Dictionary.popitem()
Example program code:
student={'age':20,'sex':'male','height':6.5}
print(student)
student.popitem()
print(student)
Output:
{'age': 20, 'sex': 'male', 'height': 6.5} {'age': 20, 'sex': 'male'}
How to check the length of the dictionary:
We can check the length of the dictionary by using len() function.
Example program code:
student={'age':20,'sex':'male','height':6.5}
print(len(student))
Output:
3
Python Sets:
In this tutorial, you will learn about python sets with examples.
What is Sets In python:
A set object is an unordered collection of distinct hashable objects. We can use this remove duplicates and check membership. It is mutable, we can add or remove items from set.
By using sets, We can able to do mathematical operations like union, intersection, difference, and symmetric difference
How to Create Sets in python:
You can create sets by placing elements in curly braces. You can add interger, float, strings. But it’s not allow mutable elements like in list, set and dictionary as elements.
Note: We need call with set object with set()functions, Otherwise it will consider as a dictionary in python.
data = {}
print(type(data))
data=set(data)
print(type(data))
data={1,2,3,4,4,5,6}
print(type(data))
Output:
<class 'dict'> <class 'set'> <class 'set'>
Python Sets Program Examples :
#program on integer and string data:
Numeric_data={1,2,3,4,4,5,6}
string_data={'ravi','raju','venkat','ravi'}
print(set(Numeric_data))
print(set(string_data))
Output:
{1, 2, 3, 4, 5, 6} {'ravi', 'raju', 'venkat'}
How to change elements in sets:
You can change elements in sets by using add(), update() and remove () functions
#python set program to add, change, remove elements from sets
numeric_data={1,2,3,4,4,5,6}
string_data={'ravi','raju','venkat','ravi'}
print(set(numeric_data))
print(set(string_data))
print("after Adding data")
#adding elements to sets
string_data.add('david')
print(numeric_data)
#updating elements to sets
numeric_data.update([7,8])
print("after Update data")
print(string_data)
#remove elements from sets
numeric_data.remove(7)
string_data.remove('david')
print("after remove data")
print(numeric_data)
print(string_data)
Output:
{1, 2, 3, 4, 5, 6} {'ravi', 'raju', 'venkat'} after Adding data {1, 2, 3, 4, 5, 6} after Update data {'ravi', 'raju', 'venkat', 'david'} after remove data {1, 2, 3, 4, 5, 6, 8} {'ravi', 'raju', 'venkat'}
Python Inbuilt Functions:
Python has 69 built-in functions to make it easy programming. No need to write code again for these scenarios.
Here are the list of functions
S.no | Built-in Functions | Function Description |
1 | __import__() | This function is used to import modules |
2 | abs() | This function returns absolute value if it’s integer or float number , if it’s complex number it returns magnitude |
3 | all() | This function returns True if all items in an iterable object are true |
4 | any() | This function returns True if any item in an iterable object is true |
5 | ascii() | The function returns a readable version of any object like Strings, Tuples, Lists, etc and It will replace any non-ascii characters with escape characters |
6 | bin() | This function returns binary value of number |
7 | bool() | This function returns true if the value is there and it returns false if the value is zero or none |
8 | breakpoint() | This function drops you into the debugger |
9 | bytearray() | This function returns an array of objects |
10 | bytes() | This function returns bytes object |
11 | callable() | This function returns if specific object is callable otherwise it will return False |
12 | chr() | This function returns a character from specified character code |
13 | classmethod() | This function converts a method to classmethod |
14 | compile() | This function will compile sourse into code and Code objects can be executed by exec() or eval() |
15 | complex() | This function returns complex value with real and imaginary values |
16 | delattr() | This function deletes the named attribute and provides an object allows it |
17 | dict() | This function returns a dictionary |
18 | dir() | This function returns a specific list of object properties and methods |
19 | divmod() | This function returns a quotient and the remainder values |
20 | enumerate() | This function returns an enumerate object |
21 | eval() | This function evaluates and executes an expression |
22 | exec() | This function execute a specific code |
23 | filter() | This function returns filter items from an iterative object |
24 | float() | This function returns a float value |
25 | format() | This function formats a specific value |
26 | frozenset() | This function returns a frozenset object |
27 | getattr() | This function Returns a value of the specified attribute (property or method) |
28 | globals() | This function Returns a dictionary representing the current global symbol table |
29 | hasattr() | This function takes arguments as objects and strings, Returns True if the specified object has the specified attribute |
30 | hash() | This function returns a hash value for specific object |
31 | help() | This function executes and built-in help system |
32 | hex() | This function returns hexadecimal value |
33 | id() | This function returns the id of an object |
34 | input() | This function will collect the data from user inputs and save it |
35 | int() | This function returns integar value |
36 | isinstance() | This function true if the specified object is an instance of a specified object is true otherwise False |
37 | issubclass() | This function true if the specified class is a subclass of a specified object otherwise False |
38 | iter() | This function returns iterator object |
39 | len() | This fucntion return length of an object |
40 | list() | This function returns a list |
41 | locals() | This function returns updated dictionary of the current local symbol table |
42 | map() | This function specified iterator with the specified function applied to each item |
43 | max() | This function returns largest value from iterative object |
44 | memoryview() | This function returns a memory view of an object created from the given argument. |
45 | min() | This function returns smallest value from iterative object |
46 | next() | This function returns a next item from iterator |
47 | object() | This function returns a object value |
48 | oct() | This function returns a octal value from number |
49 | open() | This function opens a files and returns a file object |
50 | ord() | This function return Unicode of the specified character from interger |
51 | pow() | This function returns the value of a to the power of b |
52 | print() | This function prints data to standard ouput devices |
53 | property() | This function returns a property attribute |
54 | range() | This function returns a sequence of number starting from 0 and then it incremented by 1 |
55 | repr() | This function return a string containing a printable representation of an object |
56 | reversed() | This function returns a reverse iterator. Object must be sequence |
57 | round() | This function returnes rounded value |
58 | set() | This function returns sets object |
59 | setattr() | This function sets an attribute (property/method) of an object |
60 | slice() | This function returns a slice object |
61 | sorted() | This function returns a sorted list |
62 | staticmethod() | This function converts a method to staticmethod() |
63 | str() | This function returns a string object |
64 | sum() | This function sum values from iterative object |
65 | super() | This function return a proxy object that delegates method calls to a parent or sibling class of type |
66 | tuple() | This function returns a tuple object |
67 | type() | This function returns dataype of value |
68 | vars() | This function returns the __dict__ property of an object |
69 | zip() | This function returns an iterator, from two or more iterators |