Python Programming for basic beginners.pptx

Python Programming
By
Prof. Pallavi Joshi

Python:
• It is a General Purpose Programming Language
Use:
• Desktop App, Web App, Machine Learning
App, Data Science App
History:
• 1991, Guido Van Rossum(GvR), Free
Features:
• Simple, Easy, Dynamically Typed
Software:
• Editor Notepad + Python Software(python.org)
Coding:
• Input(): to get input from user
• Int(): to get integer from user
• Float(): to get float from user
• Print(): to print output on screen
• Round(): to control fractional part

What is Python Variables?
• Variable is a name that is used to
refer to memory location.
• Python variable is also known as
an identifier and used to hold
value.
Rules for defining Variables:
• The first character of the variable must
be an alphabet or underscore ( _ ).
• All the characters except the first
character may be an alphabet of lower-
case(a-z), upper-case (A-Z),
underscore, or digit (0-9).
• Identifier name must not contain any
white-space, or special character (!, @,
#, %, ^, &, *).
• Identifier name must not be similar to
any keyword defined in the language.
• Identifier names are case sensitive; for
example, my name, and MyName is not
the same.
• Examples of valid identifiers: a123, _n,
n_9, etc.
Declaring Variable and Assigning Value:
• create a variable at the required time.
• The equal (=) operator is used to
assign value to a variable.
• Example : a=50

Python Data Types
• Variables can hold values, and every
value has a data-type
• Python is a dynamically typed
language
• do not need to define the type of the
variable while declaring it
• Example: a=5 , a holds integer value 5
a=10
b="Hi Python"
c = 10.5
print(type(a))
print(type(b))
print(type(c))
Sample code to find data type
<type 'int’>
<type 'str’>
<type 'float'>

Numbers:
• Number stores numeric values.
• integer, float, and complex values are
Numbers data-type
• type() function to know the data-type of
the variable
a=5
print("The type of a", type(a))
b=40.5
print("The type of b", type(b))
c=1+3j
print("The type of c", type(c))
The type of a <class 'int’>
The type of b <class 'float’>
The type of c <class 'complex'>
String:
• string can be defined as the sequence
of characters represented in the
quotation marks. (“abc”)
• the operator + is used to concatenate
two strings
• operator * is known as a repetition
operator
str1='hello javatpoint' #string str1
str2=' how are you' #string str2
print(str1[0:2]) #printing first two character u
sing slice operator
print(str1[4]) #printing 4th character of the s
tring
print(str1*2) #printing the string twice
print(str1+str2) #printing the concatenation o
f str1 and str2
he
o
hello javatpointhello javatpoint
hello javatpoint how are you

Python Strings
• Strings in python are
surrounded by either single
quotation marks, or double
quotation marks.
• Example: ‘Hello’ Or “Hello”
Assign String to Variable
a = "Hello"
print(a)
Multiline String(with three double
quotes)
a = """You can assign a
multiline string to a variable
by using three quotes."""
print(a)
Multiline String(with three single
quotes)
a = '''You can assign a
multiline string to a
variable by using three
quotes.'''
print(a)
Strings are Arrays
• Python does not have a
character data type, a
single character is
simply a string with a
length of 1.
a = "Hello, World!"
print(a[1])
Looping through a string
for x in "banana":
print(x)
b
a
n
a
n
a

Strings Length
a = "Hello, World!"
print(len(a))
• The len() function
returns the length of a
string
13
Check String
• To check if a certain
phrase or character is
present in a string, we
can use the keyword in
• Example: Check if
"free" is present in the
following text
txt = "The best things
in life are free!"
print("free" in txt)
True
Example:
Check if "expensive" is NOT
present in the following text
txt = "The best things in
life are free!"
print("expensive" not in
txt)
True

Python List
• Lists are used to store multiple
items in a single variable
• Example: Create a Lists
thislist =
["apple", "banana", "cherry"]
print(thislist)
['apple', 'banana', 'cherry']
Access Items
thislist =
print(thislist[1])
Range of index
thislist =
["apple", "banana", "cherry"
, "orange", "kiwi", "melon",
"mango"]
print(thislist[2:5])
['cherry', 'orange', 'kiwi']
Change list items
• To change the value of a
specific item, refer to the
index number.
thislist =
thislist[1] = "blackcurrant"
print(thislist)
Change range of item value
• Change the values
"banana" and "cherry" with
the values "blackcurrant"
and "watermelon":
thislist =
["apple", "banana", "cher
ry", "orange", "kiwi", "m
ango"]
thislist[1:3] =
["blackcurrant", "waterme
lon"]
print(thislist)
['apple', 'blackcurrant',
'watermelon', 'orange',
'kiwi', 'mango']

Add list item
• To add an item to the
end of the list, use
the append() method
thislist =
thislist.append("orange")
print(thislist)
['apple', 'banana', 'cherry',
'orange']
Insert into list
• To insert a list item at a
specified index, use
the insert() method
thislist =
thislist.insert(1, "orange")
print(thislist)
['apple', 'orange', 'banana',
'cherry']
Extend List
• To append elements
from another list to
the current list, use
the extend() method
thislist =
["apple", "banana", "cherr
y"]
tropical =
["mango", "pineapple", "pa
paya"]
thislist.extend(tropical)
print(thislist)
['apple', 'banana',
'cherry', 'mango',
'pineapple', 'papaya']

Remove specified item
• The remove() method
removes the specified
item.
thislist =
thislist.remove("banana")
print(thislist)
['apple', 'cherry']
thislist =
["apple", "banana", "cherry"
]
thislist.pop(1)
print(thislist)
Remove specified index
• The pop() method
index.
['apple', 'cherry']
Remove specified index
• The del keyword also
index
thislist =
["apple", "banana", "cherr
y"]
del thislist[1]
print(thislist)
['apple', 'cherry']

Sort list Copy List Join List
• List objects have
a sort() method that will
sort the list
alphanumerically, ascending,
by default
thislist =
["orange", "mango", "kiwi",
"pineapple", "banana"]
thislist.sort()
print(thislist)
['banana', 'kiwi', 'mango',
'orange', 'pineapple']
• A copy of a list with
the copy() method.
• A copy of a list with
the list() method
thislist =
ry"]
mylist = thislist.copy()
print(mylist)
thislist =
ry"]
mylist = list(thislist)
print(mylist)
['apple', 'banana',
'cherry']
• using the + operator
• Using append()
• Using extend()
list1 =
["a", "b" , "c"]
list2 = [1, 2, 3]
list3 = list1 + list2
print(list3)
for x in list2:
list1.append(x)
print(list1)
list1.extend(list2)
print(list1)

Python Tuples Tuple Items Access Tuple Items
• Tuples are used to store
multiple items in a single
variable
• A tuple is a collection which
is ordered and
unchangeable
• Tuples are written with
round brackets
thistuple = ("apple",
"banana", "cherry")
print(thistuple)
('apple', 'banana', 'cherry')
• Tuple items are ordered,
unchangeable, and allow
duplicate values.
• Tuple items are indexed, the
first item has index [0], the
second item has index [1] etc.
• ex. Allow duplicates
"banana", "cherry",
"apple", "cherry")
print(thistuple) banana
• access tuple items by
referring to the index
number, inside square
brackets
"banana", "cherry")
print(thistuple[1])
('apple', 'banana', 'cherry',
'apple', 'cherry')

Negative Indexing Range of Indexes Access Tuple Items
• Negative indexing means
start from the end.
• -1 refers to the last item, -
2 refers to the second last
item etc.
"banana", "cherry")
print(thistuple[-1])
cherry
• specify a range of indexes by
specifying where to start and
where to end the range.
• When specifying a range, the
return value will be a new
tuple with the specified items
• The search will start at index 2
(included) and end at index 5
(not included).
"banana", "cherry",
"orange", "kiwi", "melon",
"mango")
print(thistuple[2:5])
banana
• access tuple items by
referring to the index
number, inside square
brackets
"banana", "cherry")
print(thistuple[1])
('cherry', 'orange', 'kiwi')

Arithmetic Operator
Operator Description
+ (Addition) add two operands. For example, if a = 10, b = 10 => a+b = 20
- (Subtraction) subtract the second operand from the first operand. If the first
operand is less than the second operand, the value results
negative. For example, if a = 20, b = 5 => a - b = 15
/ (divide) It returns the quotient after dividing the first operand by the
second operand. For example, if a = 20, b = 10 => a/b = 2.0
* (Multiplication) It is used to multiply one operand with the other. For example, if a
= 20, b = 4 => a * b = 80
% (reminder) It returns the reminder after dividing the first operand by the
second operand. For example, if a = 20, b = 10 => a%b = 0

Comparison Operator
== If two operands is equal
!= If operands is not equal.
<= if first operand is smaller than or equal to second
operand.
>= if first operand is greater than or equal to second
operand.
> If the first operand is greater than the second
operand.
< If the first operand is less than the second operand.

Logical Operator
and The condition will also be true if the expression is true. If the two
expressions a and b are the same, then a and b must both be true.
or The condition will be true if one of the phrases is true. If a and b are
the two expressions, then an or b must be true if and is true and b is
false.
not If an expression a is true, then not (a) will be false and vice versa.

Membership Operator
in Returns True if a sequence with the specified value is present in the
object. Example: x in y
not in Returns True if a sequence with the specified value is not present in
the object Example: x not in y

Identity Operator
Oper
ator
Description
is Returns true if both variables are the same
object. Example: x is y
is not Returns true if both variables are not the
same object. Example x is not y
Operator Precedence
Operat
or
Description
() Parentheses
** Exponentiation
* / Multiplication and division
+ - Addition and subtraction
How to Remember: PREMDAS

If Condition Elif condition Else condition
"if the previous conditions were
not true, then try this condition".
Example
a = 33
b = 200
if b > a:
print("b is greater than a")
Example:
a = 33
b = 33
if b > a:
print("b is greater than
a")
elif a == b:
print("a and b are
equal")
Example:
a = 200
b = 33
if b > a:
elif a == b:
print("a and b are equal")
else:
print("a is greater than b")
Indentation
Example
a = 33
b = 200
if b > a:

While Loop
• With the while loop we can execute a set
of statements as long as a condition is
true.
• Example: your own Python Ser
Print i as long as i is less than 6:
i = 1
while i < 6:
print(i)
i += 1
1
2
3
4
5
The Break statement
• With the break statement we can stop the
loop even if the while condition is true:
• Example
Exit the loop when i is 3:
i = 1
while i < 6:
print(i)
if i == 3:
break
i += 1
1
2
3

The Continue Statement
• With the continue statement we can
stop the current iteration, and
continue with the next.
• Example
Continue to the next iteration if i is 3:
i = 0
while i < 6:
i += 1
if i == 3:
continue
print(i)
1
2
4
5
6
The Else Statement
• With the else statement we can run
a block of code once when the
condition no longer is true:
• Example
• Print a message once the condition
is false:
i = 1
while i < 6:
print(i)
i += 1
else:
print("i is no longer less than 6")
1
2
3
4
5
i is no longer less than 6

For Loop Looping Through a String
• A for loop is used for iterating over a
sequence
• Example
Print each fruit in a fruit list:
fruits = ["apple", "banana", "cherry"]
for x in fruits:
print(x)
apple
banana
cherry
• Even strings are iterable objects, they
contain a sequence of characters:
• Example
Loop through the letters in the word
"banana":
for x in "banana":
print(x)
b
a
n
a
n
a

The break Statement The continue Statement
• With the break statement we can stop
the loop before it has looped through
all the items:
• Example
Exit the loop when x is "banan":
fruits =
for x in fruits:
print(x)
if x == "banana":
break
apple
banana
• With the continue statement we can
stop the current iteration of the loop,
and continue with the next:
• Example
Do not print banana:
fruits =
for x in fruits:
if x == "banana":
continue
print(x)
apple
cherry

1. n = int(input("Enter the number of rows"))
2. # outer loop to handle number of rows
3. for i in range(0, n):
4. # inner loop to handle number of columns
5. # values is changing according to outer loop
6. for j in range(0, i + 1):
7. # printing stars
8. print("* ", end="")
9.
10. # ending line after each row
11. print()
This is the example of print simple pyramid pattern

GUI(Graphical User Interface)
● tkinter is a library for creating GUI in
Python
Coding
● Tk(): to create window
● mainloop(): to show window
● title(): to change title
● geometry(): “widthxheight
+xpos+ypos”
Widgets
● Label, Entry, Button
Width
Height
YPos
XPos

GUI(Graphical User Interface)
from tkinter import *
root= Tk()
root.geometry("1000x300+300+200")
root.mainloop()
root= Tk()
root.mainloop()

root= Tk()
root.geometry("1000x300+300+200")
root.configure(bg="Yellow")
root.mainloop()
root= Tk()
root.geometry("1000x300+300+200")
lab=Label(root, text="welcome to
Python Lab")
lab.pack()
root.mainloop()

Sample Program(Label)
root= Tk()
root.geometry("1000x300+300+200")
f=("Times New Roman",60,"bold")
lab=Label(root, text="welcome to Python
Lab", font=f, fg="red", bg="yellow")
lab.pack(pady=100)
root.mainloop()

Sample Program(Button)
root= Tk()
root.title("App by me")
root.geometry("1000x500+300+100")
f=("Times New Roman",30,"bold")
def show():
lab.configure(text="Welcome to Python Lab")
btn=Button(root, text="Click me", font=f, command=show)
btn.pack(pady=30)
lab=Label(root, font=f)
lab.pack()
root.mainloop()

root=Tk()
root.title("App by Me")
root.geometry("800x400+300+200")
f=("Arial",30,"bold")
lab=Label(root, text="Enter your name", font=f)
lab.pack(pady=10)
ent=Entry(root, font=f)
ent.pack(pady=10)
def show():
name=ent.get()
msg="Good Afternoon " +name
ans.configure(text=msg)
btn=Button(root, text="click me", font=f, command=show)
btn.pack(pady=10)
ans=Label(root, font=f)
ans.pack(pady=10)
root.mainloop()
Sample Program(Entry)

Problems
Calculate Area
Enter radius
Result:
RED
Green
Blue
Change background colour when button click
Calculate radius

Accessing Items
You can access the items of a dictionary by referring to its key name, inside square brackets:
Python Dictionaries

OUTPUT:
{'brand': 'Ford', 'model':
'Mustang', 'year': 2018}

Python Programming for basic beginners.pptx

More Related Content

Similar to Python Programming for basic beginners.pptx

Recently uploaded

Python Programming for basic beginners.pptx