Module I - Day 1

Python Foundation

Nov-Jan 2025 batch, Vikrant Patil

Date: 20 Sep 2025

Click here for All Notes

© Vikrant Patil

print("hello")

hello

Working with jupyter notebook

Another fancy way of programming python is jupyter notebook. once you launch
jupyter from console or from start menu, a browser will be launched.
Create a new notebook. To work with notebook you need to know few key strokes.

  ===========   ====================================
  keys          action                              
  ===========   ====================================
  esc+m         convert the cell to markdown        
  esc+y         convert the cell to code            
  shift+enter   execute the cell                   
  !command      execute system command from jupyter 
  ===========   ====================================

Basic Datatypes

• integer - integer (+/- 0)
• float - (real numbers, decimal numbers)
• str

3 + 5 

8

5 / 2

2.5

5 // 2 # integer division

2

5 ** 3 #this is a comment .. 5 raised to power 3

125

5.5 + 5.6

11.1

5.5 // 2

2.0

5.0 ** 5 

3125.0

64/8

8.0

5 ** 5

3125

2 ** 100

1267650600228229401496703205376

2**64-1 # c will  have this as max integer value for 64 bit integer

18446744073709551615

priotity

1 + 3 *5 # it follows similar priorities as in excel or in mathematics

16

"vikrant"

'vikrant'

'python'

'python'

"programming"

'programming'

'vikrant' + 'patil' # concatenate the added text

'vikrantpatil'

'*'*5 # this repeates the text 5 times

'*****'

'vikrant'*5

'vikrantvikrantvikrantvikrantvikrant'

3 + 5
5 ** 7 # you will see result of last line

78125

42 + 42

84

built in

• functions provided by python readily for execution

int("45")
# int - name of built in function
# () into these round parenthesis you pass the argument to function
# "45" is the argument here

45

"45" # this is text

'45'

"45" + 5

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[32], line 1
----> 1 "45" + 5

TypeError: can only concatenate str (not "int") to str

"45" + "45" 

'4545'

45 + 45

90

int("45") + int("45") # this will converted the quoted text into int and then add

90

float("45.6")

45.6

"45" # two characters 4 and 5 

'45'

45 # integer we type decimal digits for our covennince , internally it is stored as binary

45

45 + 45

90

int("45")

45

str(42) # convert objects into text

'42'

len("vikrant") # how many chars are there in the text

7

len(45) # what you intend here is to find number of digit... it is not length of number

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[44], line 1
----> 1 len(45) # what you intend here is to find number of digit... it is not length of number

TypeError: object of type 'int' has no len()

len(str(45)) # convert the integer into text first then find length of that text

2

len(  str(45)  ) # the execution order will be... inner most will be executed first

2

len(str(2**100))

31

2**100

1267650600228229401496703205376

collection

• collection of objects
• list - ordered collection of objects which can be modified
• tuple - ordered collection of objects which can not be modified (immutable object)
• dictionary - named collection of objects

list

[1, 2, 3, 4, 5, 5]

[1, 2, 3, 4, 5, 5]

variables

name = "python" # = is called as assigment operator

name # interpreter will show what this object in name

'python'

x = 42

x

42

z = 1.5

x, y = 5, 6 # you can assign multple variables in single statement

x + y

11

x

5

y

6

x = 10

y = 20

x = 30

problem think about this

x = 20
y = x
x = 30

what will be value of y after execution of all the three statements?

problem Have a look at following python statements.

    x = 10
    y = x
    x = x + 10

What will be value of y after this?

What will be value of x after executing all statements?

    x = 10
    y = x
    y = 25

collection

• collection of objects
• list - ordered collection of objects which can be modified
• tuple - ordered collection of objects which can not be modified (immutable object)
• dictionary - named collection of objects
• text - it is ordered collection of chars (text)

list

nums = [1, 1, 3, 6, 2, 4, 5, 4]

nums

[1, 1, 3, 6, 2, 4, 5, 4]

nums[0] # index starts with 0

1

names = ['vikrant', 'tushar', 'abid', 'pallavi', 'jagdish']

names[0] # indexing is done with square bracket

'vikrant'

names[1]

'tushar'

names[-1] # it will give last item

'jagdish'

names[-2] # it will give second last item

'pallavi'

names[56]

---------------------------------------------------------------------------
IndexError                                Traceback (most recent call last)
Cell In[76], line 1
----> 1 names[56]

IndexError: list index out of range

 names[0]

'vikrant'

names[-3]

'abid'

names[-5] # better access first item with names[0]

'vikrant'

len(names) # len can be used to find length of collection

5

len("vikrant")

7

len(names[0]) # lengh of the first item from names

7

name

'python'

name[0]

'p'

tuple

point = (3, 4, 8)

point

(3, 4, 8)

point[0]

3

len(point)

3

names # it is list

['vikrant', 'tushar', 'abid', 'pallavi', 'jagdish']

names[0] = "VIKRANT"

names

['VIKRANT', 'tushar', 'abid', 'pallavi', 'jagdish']

names[-1] = "JAGDISH"

names

['VIKRANT', 'tushar', 'abid', 'pallavi', 'JAGDISH']

point

(3, 4, 8)

point[0] = 0 # tuple is immutable object

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[100], line 1
----> 1 point[0] = 0 # tuple is immutable object

TypeError: 'tuple' object does not support item assignment

name

'python'

name[0]

'p'

name[0] = "P"

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[103], line 1
----> 1 name[0] = "P"

TypeError: 'str' object does not support item assignment

x = 3, 4, 5, 5  # this is also a tuple

x

(3, 4, 5, 5)

x, y = 5, 6

5, 6 # this is also tuple

(5, 6)

(5, 6)

(5, 6)

t = (2, 3, 4, 6)

t = (1, 2, 3, 4) # this not modifying , but creating new one

indexing is always done with square bracket

len(name) # round parenthesis after any name means call that object 

6

t

(1, 2, 3, 4)

t[0] 

1

t[0] = -1

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[118], line 1
----> 1 t[0] = -1

TypeError: 'tuple' object does not support item assignment

dictionary

person = ["vikrant", "prabhakar", "patil"]

person[0]

'vikrant'

person[1]

'prabhakar'

person[2]

'patil'

p = {'firstname' : "vikrant", "middlename": "prabhakar", "lastname": "patil"}

p

{'firstname': 'vikrant', 'middlename': 'prabhakar', 'lastname': 'patil'}

p['firstname']

'vikrant'

p['middlename']

'prabhakar'

p['lastname']

'patil'

point_3d = {'x': 0,   # you can separate every on new line
            'y': 10,  # give comma between every pair
            'z': 20}  # give : betwen every key and value

point_3d['x']

0

point_3d['y']

10

point_3d['z']

20

college = {"physics" : ["phy_std1", "phy_std2"],
 "chemistry" : ["chem_stud1", "chem_stud2"]}

college['physics']

['phy_std1', 'phy_std2']

ps1 = {"name" : "phy_std1",
       "place" : "place1",
       "height" : 5.6}
ps2 = {"name" : "phy_std2",
       "place" : "place2",
       "height" : 5.7}

ch1 = {"name" : "chem_std1",
       "place" : "place3",
       "height" : 6.0}
ch2 = {"name" : "chem_std2",
       "place" : "place4",
       "height" : 6.1}

college_ = {"physics": [ps1, ps2],
            "chemistry": [ch1, ch2]}

college_

{'physics': [{'name': 'phy_std1', 'place': 'place1', 'height': 5.6},
  {'name': 'phy_std2', 'place': 'place2', 'height': 5.7}],
 'chemistry': [{'name': 'chem_std1', 'place': 'place3', 'height': 6.0},
  {'name': 'chem_std2', 'place': 'place4', 'height': 6.1}]}

college_['physics'][0]

{'name': 'phy_std1', 'place': 'place1', 'height': 5.6}

college_['physics'][0]['name']

'phy_std1'

college_['physics'][1]['name']

'phy_std2'

college_['chemistry'][0]['name']

'chem_std1'

brackets

for creating the objects
- for creating a list []
- for creating a tuple ()
- for creating a dictionary {}
- for creating a set {}

for accesing always use square bracket []

list => nums[0]
tuple=> point[0]
dictionary => college['physics']

Homework

problem

• a cvs file stocks.csv looks like this. How will you represent this data in python using basic and collection data types learnt so far?

    symbol,value,high value,low value,volume
    APPLE,234.5,240.3,233.0,100
    AT&T,221.6,22.5,220.0,200
    IBM,125.7,127.3,123.0,50
    NIKE,100.5,105.0,104.0,1000