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Data Science

May 2026×Notebook lesson

Notebook converted from Jupyter for blog publishing.

01-Python Crash Course

Driptanil DattaSoftware Developer

Data types

Numbers

1 + 1

RESULT

1 * 3

RESULT

1 / 2

RESULT

0.5

2 ** 4

RESULT

4 % 2

RESULT

5 % 2

RESULT

(2 + 3) * (5 + 5)

RESULT

Variable Assignment

# Can not start with number or special characters
name_of_var = 2

x = 2
y = 3

z = x + y

RESULT

Strings

'single quotes'

RESULT

'single quotes'

"double quotes"

RESULT

'double quotes'

" wrap lot's of other quotes"

RESULT

" wrap lot's of other quotes"

Printing

x = 'hello'

RESULT

'hello'

print(x)

STDOUT

hello

num = 12
name = 'Sam'

print('My number is: {one}, and my name is: {two}'.format(one=num,two=name))

STDOUT

My number is: 12, and my name is: Sam

print('My number is: {}, and my name is: {}'.format(num,name))

STDOUT

My number is: 12, and my name is: Sam

Lists

[1,2,3]

RESULT

[1, 2, 3]

['hi',1,[1,2]]

RESULT

['hi', 1, [1, 2]]

my_list = ['a','b','c']

my_list.append('d')

my_list

RESULT

['a', 'b', 'c', 'd']

my_list[0]

RESULT

'a'

my_list[1]

RESULT

'b'

my_list[1:]

RESULT

['b', 'c', 'd']

my_list[:1]

RESULT

['a']

my_list[0] = 'NEW'

my_list

RESULT

['NEW', 'b', 'c', 'd']

nest = [1,2,3,[4,5,['target']]]

nest[3]

RESULT

[4, 5, ['target']]

nest[3][2]

RESULT

['target']

nest[3][2][0]

RESULT

'target'

Dictionaries

d = {'key1':'item1','key2':'item2'}

RESULT

{'key1': 'item1', 'key2': 'item2'}

d['key1']

RESULT

'item1'

Booleans

True

RESULT

True

False

RESULT

False

Tuples

t = (1,2,3)

t[0]

RESULT

t[0] = 'NEW'

ERROR

TypeError: 'tuple' object does not support item assignment
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-44-97e4e33b36c2> in <module>()
----> 1 t[0] = 'NEW'

Sets

{1,2,3}

RESULT

{1, 2, 3}

{1,2,3,1,2,1,2,3,3,3,3,2,2,2,1,1,2}

RESULT

{1, 2, 3}

Comparison Operators

1 > 2

RESULT

False

1 < 2

RESULT

True

1 >= 1

RESULT

True

1 <= 4

RESULT

True

1 == 1

RESULT

True

'hi' == 'bye'

RESULT

False

Logic Operators

(1 > 2) and (2 < 3)

RESULT

False

(1 > 2) or (2 < 3)

RESULT

True

(1 == 2) or (2 == 3) or (4 == 4)

RESULT

True

if,elif, else Statements

if 1 < 2:
    print('Yep!')

STDOUT

Yep!

if 1 < 2:
    print('yep!')

STDOUT

yep!

if 1 < 2:
    print('first')
else:
    print('last')

STDOUT

first

if 1 > 2:
    print('first')
else:
    print('last')

STDOUT

last

if 1 == 2:
    print('first')
elif 3 == 3:
    print('middle')
else:
    print('Last')

STDOUT

middle

for Loops

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

for item in seq:
    print(item)

STDOUT

for item in seq:
    print('Yep')

STDOUT

Yep
Yep
Yep
Yep
Yep

for jelly in seq:
    print(jelly+jelly)

STDOUT

while Loops

i = 1
while i < 5:
    print('i is: {}'.format(i))
    i = i+1

STDOUT

i is: 1
i is: 2
i is: 3
i is: 4

range()

range(5)

RESULT

range(0, 5)

for i in range(5):
    print(i)

STDOUT

list(range(5))

RESULT

[0, 1, 2, 3, 4]

list comprehension

x = [1,2,3,4]

out = []
for item in x:
    out.append(item**2)
print(out)

STDOUT

[1, 4, 9, 16]

[item**2 for item in x]

RESULT

[1, 4, 9, 16]

functions

def my_func(param1='default'):
    """
    Docstring goes here.
    """
    print(param1)

my_func

RESULT

<function __main__.my_func>

my_func()

STDOUT

default

my_func('new param')

STDOUT

new param

my_func(param1='new param')

STDOUT

new param

def square(x):
    return x**2

out = square(2)

print(out)

STDOUT

lambda expressions

def times2(var):
    return var*2

times2(2)

RESULT

lambda var: var*2

RESULT

<function __main__.<lambda>>

map and filter

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

map(times2,seq)

RESULT

<map at 0x105316748>

list(map(times2,seq))

RESULT

[2, 4, 6, 8, 10]

list(map(lambda var: var*2,seq))

RESULT

[2, 4, 6, 8, 10]

filter(lambda item: item%2 == 0,seq)

RESULT

<filter at 0x105316ac8>

list(filter(lambda item: item%2 == 0,seq))

RESULT

[2, 4]

methods

st = 'hello my name is Sam'

st.lower()

RESULT

'hello my name is sam'

st.upper()

RESULT

'HELLO MY NAME IS SAM'

st.split()

RESULT

['hello', 'my', 'name', 'is', 'Sam']

tweet = 'Go Sports! #Sports'

tweet.split('#')

RESULT

['Go Sports! ', 'Sports']

tweet.split('#')[1]

RESULT

'Sports'

RESULT

{'key1': 'item1', 'key2': 'item2'}

d.keys()

RESULT

dict_keys(['key2', 'key1'])

d.items()

RESULT

dict_items([('key2', 'item2'), ('key1', 'item1')])

lst = [1,2,3]

lst.pop()

RESULT

lst

RESULT

[1, 2]

'x' in [1,2,3]

RESULT

False

'x' in ['x','y','z']

RESULT

True

Great Job!

🐍 Python & Machine Learning 02 Python Crash Course Exercises