1691912901477_Python_Basics and list,tuple,string.pptx

Content
• Comments in Python
• Variable Declaration in Python
• Data Types in Python
• Type Conversion in Python
• Operators in Python

Comments in Python
• In general, Comments are used in a programming language to
describe the program or to hide the some part of code from
the interpreter.
• Comments in Python can be used to explain any program
code. It can also be used to hide the code as well.
• Comment is not a part of the program, but it enhances the
interactivity of the program and makes the program readable.
Python supports two types of comments:
• Single Line Comment
• Multi Line Comment

Comments in Python Cont..
Single Line Comment:
In case user wants to specify a single line comment, then comment must start
with ‘#’
Example:
# This is single line comment
print "Hello Python"
Output:
Hello Python
Multi Line Comment:
Multi lined comment can be given inside triple quotes.
Example:
'''This is
Multiline
Comment'''
print "Hello Python"
Output:
Hello Python

Variable Declaration in Python
• A variable is a named memory location in which we can store
values for the particular program.
• In other words, Variable is a name which is used to refer
memory location. Variable also known as identifier and used
to hold value.
• In Python, We don't need to declare explicitly variable in
Python. When we assign any value to the variable that
variable is declared automatically.
• In Python, We don't need to specify the type of variable
because Python is a loosely typed language.

Variable Declaration in Python Cont..
• In loosely typed language no need to specify the type of
variable because the variable automatically changes it's data
type based on assigned value.
Rules for naming variable:
• Variable names can be a group of both letters and digits, but
they have to begin with a letter or an underscore.
• It is recommended to use lowercase letters for variable name.
‘SUM’ and ‘sum’ both are two different variables.
Example: Vardemo.py
a=10 #integer
b=“python" #string
c=12.5 #float
print(a)
print(b)
print(c)
output:
$python3 Vardemo.py
10
python
12.5

Variable Declaration in Python Cont..
• Python allows us to assign a value to multiple variables and
multiple values to multiple variables in a single statement
which is also known as multiple assignment.
• Assign single value to multiple variables :
• Assign multiple values to multiple variables :
Example: Vardemo1.py
x=y=z=50
print x
print y
print z
output:
$python3 Vardemo1.py
50
50
50
Example: Vardemo2.py
a,b,c=5,10,15
print a
print b
print c
output:
$python3 Vardemo2.py
5
10
15

Data Types in Python
• In general, Data Types specifies what type of data will be
stored in variables. Variables can hold values of different data
types.
• Python is a dynamically typed or loosely typed language,
hence we need not define the type of the variable while
declaring it.
• The interpreter implicitly binds the value with its type.
• Python provides us the type () function which enables us to
check the type of the variable.

Data Types in Python Cont..
• Python provides following standard data types, those are
 Numbers
 String
Numbers:
• Number stores numeric values. Python creates Number type
variable when a number is assigned to a variable.
There are three numeric types in Python:
1. int
2. float
3. Complex

2. float:
Float or "floating point number" is a
number, positive or negative, containing
decimals.
Example:
X=1.0
Y=12.3
Z=-13.4
3. complex:
Complex numbers are written with a "j" as
the imaginary part.
Example:
A=2+5j
B=-3+4j
C=-6j
1. int:
Int, or integer, is a whole number, positive or
negative, without decimals, of unlimited
length.
Example:
a=10
b=-12
c=123456789

String:
• The string can be defined as the sequence of characters
represented in the quotation marks. In python, we can use
single, double, or triple quotes to define a string.
• In the case of string handling, the operator + is used to
concatenate two strings as the operation "hello"+"
python" returns "hello python".
Example:
S1=‘Welcome’ #using single quotes
S2=“To” #using double quotes
S3=‘’’Python’’’ #using triple quotes

Example: “datatypesdemo.py”
a=10
b=“Python"
c = 10.5
d=2.14j
print("Data type of Variable a :",type(a))
print("Data type of Variable b :",type(b))
print("Data type of Variable c :",type(c))
print("Data type of Variable d :",type(d))
Output:
python3 datatypesdemo.py
Datatype of Variable a : <class ‘int’>
Datatype of Variable b : <class ‘str’>
Datatype of Variable c : <class ‘float’>
Datatype of Variable d : <class ‘complex’>

Type Conversion in Python
• Python provides Explicit type conversion functions to directly
convert one data type to another. It is also called as Type Casting in
Python
• Python supports following functions
1. int () : This function converts any data type to integer.
2. float() : This function is used to convert any data type to a floating point
number.
3. str() : This function is used to convert any data type to a string.
Example:“Typeconversiondemo.py”
x = int(2.8)
y = int("3")
z = float(2)
s = str(10)
print(x);print(y)
print(z); print(s)
Output:
python3 typeconversiondemo.py
2
3
2
10

List in Python
• In python, a list can be defined as a collection of values or
items.
• The items in the list are separated with the comma (,) and
enclosed with the square brackets [ ].
Syntax:
listname = [ value1, value2, value3,…. ]
Example: “listdemo.py”
L1 = []
L2 = [123,"python", 3.7]
L3 = [1, 2, 3, 4, 5, 6]
L4 = ["C","Java","Python"]
print(L1)
print(L2)
print(L3)
print(L4)
Output:
python listdemo.py
[]
[123, 'python', 3.7]
[1, 2, 3, 4, 5, 6]
['C','Java','Python']

List Indexing in Python
• Like string sequence, the indexing of the python lists starts from
0, i.e. the first element of the list is stored at the 0th index, the
second element of the list is stored at the 1st index, and so on.
• The elements of the list can be accessed by using the slice
operator [].
Example:
mylist=[‘banana’,’apple’,’mango’,’tomato’,’berry’]
• mylist[0]=”banana” mylist[1:3]=[”apple”,”mango”]
• mylist[2]=”mango”

List Indexing in Python cont…
• Unlike other languages, python provides us the flexibility to use
the negative indexing also. The negative indices are counted
from the right.
• The last element (right most) of the list has the index -1, its
adjacent left element is present at the index -2 and so on until
the left most element is encountered.
Example: mylist=[‘banana’,’apple’,’mango’,’tomato’,’berry’]
• mylist[-1]=”berry” mylist[-4:-2]=[“apple”,mango”]
• mylist[-3]=”mango”

List Operators in Python
+
It is known as concatenation operator used to concatenate two
lists.
*
It is known as repetition operator. It concatenates the multiple
copies of the same list.
[]
It is known as slice operator. It is used to access the list item
from list.
[:]
It is known as range slice operator. It is used to access the range
of list items from list.
in
It is known as membership operator. It returns if a particular
item is present in the specified list.
not in
It is also a membership operator and It returns true if a
particular list item is not present in the list.

List Operators in Python cont…
Example: “listopdemo.py”
num=[1,2,3,4,5]
lang=['python','c','java','php']
print(num + lang) #concatenates two lists
print(num * 2) #concatenates same list 2 times
print(lang[2]) # prints 2nd index value
print(lang[1:4]) #prints values from 1st to 3rd index.
print('cpp' in lang) # prints False
print(6 not in num) # prints True
Output: python listopdemo.py
[1, 2, 3, 4, 5, 'python', 'c', 'java', 'php']
[1, 2, 3, 4, 5, 1, 2, 3, 4, 5]
java
['c', 'java', 'php']
False
True

How to update or change elements to a list?
• Python allows us to modify the list items by using the slice and
assignment operator.
• We can use assignment operator ( = ) to change an item or a
range of items.
Example: “listopdemo1.py”
num=[1,2,3,4,5]
print(num)
num[2]=30
print(num)
num[1:3]=[25,36]
print(num)
num[4]="Python"
print(num)
Output:
python listopdemo1.py
[1, 2, 3, 4, 5]
[1, 2, 30, 4, 5]
[1, 25, 36, 4, 5]
[1, 25, 36, 4, 'Python']

How to delete or remove elements from a list?
• Python allows us to delete one or more items in a list by using
the del keyword.
Example: “listopdemo2.py”
num = [1,2,3,4,5]
print(num)
del num[1]
print(num)
del num[1:3]
print(num)
Output:
python listopdemo2.py
[1, 2, 3, 4, 5]
[1, 3, 4, 5]
[1, 5]

List Functions & Methods in Python
• Python provides various in-built functions and methods which
can be used with list. Those are
☞ len():
• In Python, len() function is used to find the length of list,i.e it
returns the number of items in the list..
Syntax: len(list)
• len()
• max()
• min()
• sum()
• list()
Example: listlendemo.py
num=[1,2,3,4,5,6]
print("length of list :",len(num))
Output:
python listlendemo.py
length of list : 6
• sorted()
• append()
• remove()
• sort()
• reverse()
• count()
• index()
• insert()
• pop()
• clear()

List Functions & Methods in Python Cont..
☞ max ():
• In Python, max() function is used to find maximum value in the list.
Syntax: max(list)
Example: listmaxdemo.py
list1=[1,2,3,4,5,6]
list2=['java','c','python','cpp']
print("Max of list1 :",max(list1))
print("Max of list2 :",max(list2))
Output:
python listmaxdemo.py
Max of list1 : 6
Max of list2 : python

☞ min ():
• In Python, min() function is used to find minimum value in the list.
Syntax: min(list)
Example: listmindemo.py
list1=[1,2,3,4,5,6]
list2=['java','c','python','cpp']
print("Min of list1 :",min(list1))
print("Min of list2 :",min(list2))
Output:
python listmindemo.py
Min of list1 : 1
Min of list2 : c

☞ sum ():
• In python, sum() function returns sum of all values in the list. List
values must in number type.
Syntax: sum(list)
Example: listsumdemo.py
list1=[1,2,3,4,5,6]
print("Sum of list items :",sum(list1))
Output:
python listsumdemo.py
Sum of list items : 21

☞ list ():
• In python, list() is used to convert given sequence (string or tuple)
into list.
Syntax: list(sequence)
Example: listdemo.py
str="python"
list1=list(str)
print(list1)
Output:
python listdemo.py
['p', 'y', 't', 'h', 'o', 'n']

☞ sorted ():
• In python, sorted() function is used to sort all items of list in an
ascending order.
Syntax: sorted(list)
Example: sorteddemo.py
num=[1,3,2,4,6,5]
lang=['java','c','python','cpp']
print(sorted(num))
print(sorted(lang))
Output:
python sorteddemo.py
[1, 2, 3, 4, 5, 6]
['c', 'cpp', 'java', 'python']

☞ append ():
• In python, append() method adds an item to the end of the list.
Syntax: list.append(item)
where item may be number, string, list and etc.
Example: appenddemo.py
num=[1,2,3,4,5]
lang=['python','java']
num.append(6)
print(num)
lang.append("cpp")
print(lang)
Output:
python appenddemo.py
[1, 2, 3, 4, 5, 6]
['python', 'java', 'cpp']

☞ remove ():
• In python, remove() method removes item from the list. It removes
first occurrence of item if list contains duplicate items. It throws an
error if the item is not present in the list.
Syntax: list.remove(item)
Example: removedemo.py
list1=[1,2,3,4,5]
list2=['A','B','C','B','D']
list1.remove(2)
print(list1)
list2.remove("B")
print(list2)
list2.remove("E")
print(list2)
Output:
python removedemo.py
[1, 3, 4, 5]
['A', 'C', 'B', 'D']
ValueError: x not in list

☞ sort ():
• In python, sort() method sorts the list elements into descending or
ascending order. By default, list sorts the elements into ascending
order. It takes an optional parameter 'reverse' which sorts the list
into descending order.
Syntax: list.sort([reverse=true])
Example: sortdemo.py
list1=[6,8,2,4,10]
list1.sort()
print("n After Sorting:n")
print(list1)
print("Descending Order:n")
list1.sort(reverse=True)
print(list1)
Output:
python sortdemo.py
After Sorting:
[2, 4, 6, 8 , 10]
Descending Order:
[10, 8, 6, 4 , 2]

☞ reverse ():
• In python, reverse() method reverses elements of the list. i.e. the
last index value of the list will be present at 0th index.
Syntax: list.reverse()
Example: reversedemo.py
list1=[6,8,2,4,10]
list1.reverse()
print("n After reverse:n")
print(list1)
Output:
python reversedemo.py
After reverse:
[10, 4, 2, 8 , 6]

☞ count():
• In python, count() method returns the number of times an element
appears in the list. If the element is not present in the list, it
returns 0.
Syntax: list.count(item)
Example: countdemo.py
num=[1,2,3,4,3,2,2,1,4,5,8]
cnt=num.count(2)
print("Count of 2 is:",cnt)
cnt=num.count(10)
print("Count of 10 is:",cnt) Output:
python countdemo.py
Count of 2 is: 3
Count of 10 is: 0

☞ index():
• In python, index () method returns index of the passed element. If
the element is not present, it raises a ValueError.
• If list contains duplicate elements, it returns index of first
occurred element.
• This method takes two more optional parameters start and end
which are used to search index within a limit.
Syntax: list. index(item [, start[, end]])
Example: indexdemo.py
list1=['p','y','t','o','n','p']
print(list1.index('t'))
Print(list1.index('p'))
Print(list1.index('p',3,10))
Print(list1.index('z')) )
Output:
python indexdemo.py
2
0
5
Value Error

☞ insert():
• In python, insert() method inserts the element at the specified
index in the list. The first argument is the index of the element
before which to insert the element.
Syntax: list.insert(index,item)
Example: insertdemo.py
num=[10,20,30,40,50]
num.insert(4,60)
print(num)
num.insert(7,70)
print(num)
Output:
python insertdemo.py
[10, 20, 30, 40, 60, 50]
[10, 20, 30, 40, 60, 50, 70]

☞ pop():
• In python, pop() element removes an element present at specified
index from the list.
Syntax: list.pop(index)
Example: popdemo.py
num=[10,20,30,40,50]
num.pop()
print(num)
num.pop(2)
print(num)
num.pop(7)
print(num)
Output:
python popdemo.py
[10, 20, 30, 40]
[10, 20, 40]
IndexError: Out of range

☞ clear():
• In python, clear() method removes all the elements from the list.
It clears the list completely and returns nothing.
Syntax: list.clear()
Example: cleardemo.py
num=[10,20,30,40,50]
num.clear()
print(num)
Output:
python cleardemo.py
[ ]

Tuple in Python
• In python, a tuple is a sequence of immutable elements or items.
• Tuple is similar to list since the items stored in the list can be
changed whereas the tuple is immutable and the items stored in
the tuple cannot be changed.
• A tuple can be written as the collection of comma-separated
values enclosed with the small brackets or parantheses ( ).
Syntax: var = ( value1, value2, value3,…. )
Example: “tupledemo.py”
t1 = ()
t2 = (123,"python", 3.7)
t3 = (1, 2, 3, 4, 5, 6)
t4 = ("C",)
print(t1)
print(t2)
print(t3)
print(t4)
Output:
python tupledemo.py
()
(123, 'python', 3.7)
(1, 2, 3, 4, 5, 6)
('C',)

Tuple Indexing in Python
• Like list sequence, the indexing of the python tuple starts from
0, i.e. the first element of the tuple is stored at the 0th index,
the second element of the tuple is stored at the 1st index, and
so on.
• The elements of the tuple can be accessed by using the slice
operator [].
Example:
mytuple=(‘banana’,’apple’,’mango’,’tomato’,’berry’)
• mytuple[0]=”banana” mytuple[1:3]=[”apple”,”mango”]
• mytuple[2]=”mango”

Tuple Indexing in Python cont…
• Unlike other languages, python provides us the flexibility to use
the negative indexing also. The negative indices are counted
from the right.
• The last element (right most) of the tuple has the index -1, its
adjacent left element is present at the index -2 and so on until
the left most element is encountered.
Example: mytuple=[‘banana’,’apple’,’mango’,’tomato’,’berry’]
• mytuple[-1]=”berry” mytuple[-4:-2]=[“apple”,mango”]
• mytuple[-3]=”mango”

Tuple Operators in Python
+
It is known as concatenation operator used to concatenate two
tuples.
*
It is known as repetition operator. It concatenates the multiple
copies of the same tuple.
[]
It is known as slice operator. It is used to access the item from
tuple.
[:]
It is known as range slice operator. It is used to access the range
of items from tuple.
in
It is known as membership operator. It returns if a particular
item is present in the specified tuple.
not in
It is also a membership operator and It returns true if a
particular item is not present in the tuple.

Tuple Operators in Python cont…
Example: “tupleopdemo.py”
num=(1,2,3,4,5)
lang=('python','c','java','php')
print(num + lang) #concatenates two tuples
print(num * 2) #concatenates same tuple 2 times
print(lang[2]) # prints 2nd index value
print(lang[1:4]) #prints values from 1st to 3rd index.
print('cpp' in lang) # prints False
print(6 not in num) # prints True
Output: python tupleopdemo.py
(1, 2, 3, 4, 5, 'python', 'c', 'java', 'php')
(1, 2, 3, 4, 5, 1, 2, 3, 4, 5)
java
('c', 'java', 'php')
False
True

How to add or remove elements from a tuple?
• Unlike lists, the tuple items cannot be updated or deleted as
tuples are immutable.
• To delete an entire tuple, we can use the del keyword with the
tuple name.
Example: “tupledemo1.py”
tup=('python','c','java','php')
tup[3]="html"
print(tup)
del tup[3]
print(tup)
del tup
Output:
python tupledemo1.py
'tuple' object does not
support item assignment
'tuple' object doesn't
support item deletion

Tuples Functions & Methods in Python
• Python provides various in-built functions and methods which
can be used with tuples. Those are
☞ len():
• In Python, len() function is used to find the length of tuple,i.e it
returns the number of items in the tuple.
Syntax: len(tuple)
• len()
• max()
• min()
• sum()
Example: lendemo.py
num=(1,2,3,4,5,6)
print("length of tuple :",len(num))
Output:
python lendemo.py
length of tuple : 6
• tuple()
•sorted()
• count()
• index()

Tuple Functions & Methods in Python Cont..
☞ max ():
• In Python, max() function is used to find maximum value in the
tuple.
Syntax: max(tuple)
Example: maxdemo.py
t1=(1,2,3,4,5,6)
t2=('java','c','python','cpp')
print("Max of Tuple t1 :",max(t1))
print("Max of Tuple t2 :",max(t2))
Output:
python maxdemo.py
Max of Tuple t1 : 6
Max of Tuple t2 : python

☞ min ():
• In Python, min() is used to find minimum value in the tuple.
Syntax: min(tuple)
Example: mindemo.py
t1=(1,2,3,4,5,6)
t2=('java','c','python','cpp')
print("Min of Tuple t1 :",min(t1))
print("Min of Tuple t2 :",min(t2))
Output:
python mindemo.py
Min of Tuple t1 : 1
Min of Tuple t2 : c

☞ sum ():
• In python, sum() function returns sum of all values in the tuple. The
tuple values must in number type.
Syntax: sum(tuple)
Example: sumdemo.py
t1=(1,2,3,4,5,6)
print("Sum of tuple items :",sum(t1))
Output:
python sumdemo.py
Sum of tuple items : 21

☞ tuple ():
• In python, tuple() is used to convert given sequence (string or list)
into tuple.
Syntax: tuple(sequence)
Example: tupledemo.py
str="python"
t1=tuple(str)
print(t1)
num=[1,2,3,4,5,6]
t2=tuple(num)
print(t2)
Output:
python tupledemo.py
('p', 'y', 't', 'h', 'o', 'n‘)
(1, 2, 3, 4, 5, 6)

☞ sorted ():
• In python, sorted() function is used to sort all items of tuple in an
ascending order.
Syntax: sorted(tuple)
Example: sorteddemo.py
num=(1,3,2,4,6,5)
lang=('java','c','python','cpp')
print(sorted(num))
print(sorted(lang))
Output:
python sorteddemo.py
(1, 2, 3, 4, 5, 6)
('c', 'cpp', 'java', 'python')

☞ count():
• In python, count() method returns the number of times an element
appears in the tuple. If the element is not present in the tuple, it
returns 0.
Syntax: tuple.count(item)
Example: countdemo.py
num=(1,2,3,4,3,2,2,1,4,5,8)
cnt=num.count(2)
print("Count of 2 is:",cnt)
cnt=num.count(10)
print("Count of 10 is:",cnt) Output:
python countdemo.py
Count of 2 is: 3
Count of 10 is: 0

☞ index():
• In python, index () method returns index of the passed element. If
the element is not present, it raises a ValueError.
• If tuple contains duplicate elements, it returns index of first
occurred element.
• This method takes two more optional parameters start and end
which are used to search index within a limit.
Syntax: tuple.index(item [, start[, end]])
Example: indexdemo.py
t1=('p','y','t','o','n','p')
print(t1.index('t'))
Print(t1.index('p'))
Print(t1.index('p',3,10))
Print(t1.index('z')) )
Output:
python indexdemo.py
2
0
5
Value Error

Strings in Python
• In python, strings can be created by enclosing the character or
the sequence of characters in the quotes.
• Python allows us to use single quotes, double quotes, or triple
quotes to create strings.
• In python, strings are treated as the sequence of characters
which means that python doesn't support the character data
type instead a single character written as 'p' is treated as the
string of length 1.
Example:
str1 = 'Hello Python'
str2 = "Hello Python"
str3 = '''Hello Python'''

String Indexing in Python
• Like other programming languages, the indexing of the python strings
starts from 0. For example, the string "HELLO" is indexed as given in
the below figure.
str="HELLO"
str[0]=H
str[1]=E
str[4]=O
• Python allows negative indexing for its sequences.
• The index of -1 refers to the last item, -2 to the second last item and
so on.
str[-1]=O
str[-2]=L
str[-4]=E

String Operators in Python
+ It is known as concatenation operator used to join the strings.
* It is known as repetition operator. It concatenates the multiple copies
of the same string.
[ ] It is known as slice operator. It is used to access the sub-strings of a
particular string.
[ : ] It is known as range slice operator. It is used to access the characters
from the specified range.
in It is known as membership operator. It returns if a particular sub-
string is present in the specified string.
not in It is also a membership operator and does the exact reverse of in. It
returns true if a particular substring is not present in the specified
string.
r/R It is used to specify the raw string. To define any string as a raw string,
the character r or R is followed by the string. Such as "hello n
python".
% It is used to perform string formatting. It makes use of the format
specifies used in C programming like %d or %f to map their values in
python.

String Operators in Python cont…
Example: “stropdemo.py”
str1 = "Hello"
str2 = " World"
print(str1*3) # prints HelloHelloHello
print(str1+str2) # prints Hello world
print(str1[4]) # prints o
print(str1[2:4]) # prints ll
print('w' in str1) # prints false as w is not present in str1
print('Wo' not in str2) # prints false as Wo is present in str2.
print(r'Hellon world') # prints Hellon world as it is written
print("The string str1 : %s"%(str1)) # prints The string str : Hello
Output: python ifdemo.py
HelloHelloHello
Hello World
o
ll
False
False
Hellon world
The string str1 : Hello

String Functions & Methods in Python
• Python provides various in-built functions & methods that are
used for string handling. Those are
☞ len():
• In python, len() function returns length of the given string.
Syntax: len(string)
• len()
• lower()
• upper()
• replace()
• join()
• split()
• find()
•index()
• isalnum()
• isdigit()
• isnumeric()
• islower()
• isupper()
Example: strlendemo.py
str1="Python Language"
print(len(str1))
Output:
python strlendemo.py
15

String Functions & Methods in Python Cont..
☞ lower ():
• In python, lower() method returns all characters of given string in
lowercase.
Syntax:
str.lower()
☞ upper ():
• In python, upper() method returns all characters of given string in uppercase.
Syntax:
str.upper()
Example: strlowerdemo.py
str1="PyTHOn"
print(str1.lower())
Output:
python strlowerdemo.py
python
Example: strupperdemo.py
str="PyTHOn"
print(str.upper())
Output:
python strupperdemo.py
PYTHON

☞ replace()
• In python, replace() method replaces the old sequence of
characters with the new sequence.
Syntax: str.replace(old, new[, count])
Example: strreplacedemo.py
str = "Java is Object-Oriented Java"
str2 = str.replace("Java","Python")
print("Old String: n",str)
print("New String: n",str2)
str3 = str.replace("Java","Python",1)
print("n Old String: n",str)
print("New String: n",str3)
Output: python strreplacedemo.py
Old String: Java is Object-Oriented and Java
New String: Python is Object-Oriented and Python
Old String: Java is Object-Oriented and Java
New String: Python is Object-Oriented and Java

☞ split():
• In python, split() method splits the string into a comma separated list.
The string splits according to the space if the delimiter is not provided.
Syntax: str.split([sep="delimiter"])
Example: strsplitdemo.py
str1 = "Python is a programming language"
str2 = str1.split()
print(str1);print(str2)
str1 = "Python,is,a,programming,language"
str2 = str1.split(sep=',')
print(str1);print(str2)
Output: python strsplitdemo.py
Java is a programming language
['Java', 'is', 'a', 'programming', 'language']
Java, is, a, programming, language
['Java', 'is', 'a', 'programming', 'language']

☞ find():
• In python, find() method finds substring in the given string and returns
index of the first match. It returns -1 if substring does not match.
Syntax: str.find(sub[, start[,end]])
Example: strfinddemo.py
str1 = "python is a programming language"
str2 = str1.find("is")
str3 = str1.find("java")
str4 = str1.find("p",5)
str5 = str1.find("i",5,25)
print(str2,str3,str4,str5)
Output:
python strfinddemo.py
7 -1 12 7

☞ index():
• In python, index() method is same as the find() method except it returns
error on failure. This method returns index of first occurred substring
and an error if there is no match found.
Syntax: str. index(sub[, start[,end]])
Example: strindexdemo.py
str1 = "python is a programming language"
str2 = str1.index("is")
print(str2)
str3 = str1.index("p",5)
print(str3)
str4 = str1.index("i",5,25)
print(str4)
str5 = str1.index("java")
print(str5)
Output:
python strindexdemo.py
7
12
7
Substring not found

☞ isalnum():
• In python, isalnum() method checks whether the all characters of the
string is alphanumeric or not.
• A character which is either a letter or a number is known as
alphanumeric. It does not allow special chars even spaces.
Syntax: str.isalnum()
Example: straldemo.py
str1 = "python"
str2 = "python123"
str3 = "12345"
str4 = "python@123"
str5 = "python 123"
print(str1. isalnum())
Output:
python straldemo.py
True
True
True
False
False

☞ isdigit():
• In python, isdigit() method returns True if all the characters in the string
are digits. It returns False if no character is digit in the string.
Syntax: str.isdigit()
Example: strdigitdemo.py
str1 = "12345"
str2 = "python123"
str3 = "123-45-78"
str4 = "IIIV"
str5 = "/u00B23" # 23
str6 = "/u00BD" # 1/2
print(str1.isdigit())
Output:
python strdigitldemo.py
True
False
False
False
True
False

☞ isnumeric():
• In python, isnumeric() method checks whether all the characters of the
string are numeric characters or not. It returns True if all the characters
are numeric, otherwise returns False.
Syntax: str. isnumeric()
Example: strnumericdemo.py
str1 = "12345"
str2 = "python123"
str3 = "123-45-78"
str4 = "IIIV"
str5 = "/u00B23" # 23
str6 = "/u00BD" # 1/2
print(str1.isnumeric())
Output:
python strnumericldemo.py
True
False
False
False
True
True

☞ islower():
• In python, islower() method returns True if all characters in the string
are in lowercase. It returns False if not in lowercase.
Syntax: str.islower()
Example: strlowerdemo.py
str1 = "python"
str2="PytHOn"
str3="python3.7.3"
print(str1.islower())
Output:
python strlowerldemo.py
True
False
True

☞ isupper():
• In python string isupper() method returns True if all characters in the
string are in uppercase. It returns False if not in uppercase.
Syntax: str.isupper()
Example: strupperdemo.py
str1 = "PYTHON"
str2="PytHOn"
str3="PYTHON 3.7.3"
print(str1.isupper())
Output:
python strupperldemo.py
True
False
True

1691912901477_Python_Basics and list,tuple,string.pptx

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