training

2+1

4%3





```
# This is formatted as code
```



a=5

a=a+a

a

a+a

type(a)



indexing n slicing with string

mystring = " hello World"

mystring



indexing

mystring[0]

mystring="Hello World"

mystring

mystring[0]

mystring[4]

mystring[5]

slicing

mystring[:3]

mystring[2:]

mystring[3:6]

mystring[1:5]

mystring[-2]

Step size

mystring[::]

mystring[::-2]

mystring[2:7:2]

mystring[2:4:-3]

mystring[2::-3]
2+1

4%3





```
# This is formatted as code
```



a=5

a=a+a

a

a+a

type(a)



indexing n slicing with string

mystring = " hello World"

mystring



indexing - single charachter of string

mystring[0]

mystring="Hello World"

mystring

mystring[0]

mystring[4]

mystring[5]



slicing - subsection of string

mystring[:3]

mystring[2:]

mystring[3:6]

mystring[1:5]

mystring[-2]

Step size

mystring[::]

mystring[::-2]

mystring[2:7:2]

mystring[2:4:-3]

mystring[2::-3]

my_income = 1000
tax_rate = 0.1
my_tax = my_income * tax_rate

my_tax

print("Hello me")

print("hello \nme \nyou")

len("hello")

print('hello \tme')

string = "Hello world"

string[-3]

string = "tinker"

string[1:4]



string properties

     

immunibility

name="sam"

n#ame[0]=p

name[1]

last_letters = name[1:]

last_letters

'p'+last_letters

x='Hello world'

x+'its me'

letter='z'

letter*5

2+3

'2'+'3'

x= 'Hello World'

x.upper()

x.lower()

x.split()

x.split('l')



formatting with .format method

print('This is a foc {}'.format('Inserted'))

print('This {c} {b} {f}'.format(f='fox', b='brown', c='quick'))

print('This {f} {b} {f}'.format(f='fox', b='brown', c='quick'))



float formatting follows "{value:width.precision f}"

result=100/777

result

print("This value is {}".format(result))

print("This value is {r:1.3f}".format(r=result))

print("This value is {r:10.3f}".format(r=result))

print("This value is {r:7.3f}".format(r=10000.3456677))

name ="sam"

print(f'The name is {name}')

name="sunny"
age="20"

print(f'{name} is {age} years old.')



**LIST **

MY_LIST = [1,2,3]

len(MY_LIST)

my_length = ['String',30, 60.2 ]

len(my_length)

my_length[0]

my_length[2]

my_length[1:]

my_length[:-1]

another_list = ['about', 'us' ]

my_length + another_list

my_new_list = my_length + another_list

my_new_list

my_new_list[0]

my_new_list.append('six')

my_new_list

my_new_list.pop()

my_new_list

poped_item = my_new_list.pop()

poped_item

my_new_list.pop(1)

A_list=['1','2','5','4','3']
B_list = ['a','b','c','f','e','d']

B_list.reverse()

A_list.sort()



ry

**dictionary vs list** 
Disctionary: unordered mapping for storing objects | its a key-value pair hence help user to grab objects without knowing the index location.
it uses curly braces{} | tuples use parathesis() | list uses []
**list**: store object in an ordered sequence | if knows loacation u can retreive it 

my_dict = {'key1': 'value1', 'key2': 'value2','key3': 'value3'}

my_dict

my_dict['key1']

price_value = {'apple': '20', 'sunny': '30','copper': '40'}

price_value ['apple']

my_dicti = {'key1': 123, 'key2': [1,2,3],'key3':{'inside_key':100}}

my_dicti['key2']

my_dicti['key3']['inside_key']

d={'key1':['a','b','c']}

d

d ['key1'][2]

d ['key1'][2].upper()

d ['key1'][2].lower()

d1= {'key1':100,'key2':200}

d1

d1['key3']= 300

d1

d1['key1']= 400

d1

d1.keys()

d1.values()

d1.items()



TUPLES  same as list but only difference is immutability, once  a value inside it cant be reassigned to protect it from getting altered as in closed set, they are always in ()

t= (1,2,3)

len(t)

t=('one',2)

t[0]

t=('a','a','b')

t[0]

t.count('a')

t.index('b')

my_list= ['one','two','three']

my_list

my_list[0]='new'

my_list

t

t[0]='one'



**set** they are unordered collection of unique elements, meaning there can be only one representative of same value. values only

my_set = set()

my_set

my_set.add(1)

my_set

my_set.add(2)

my_set.add(3)

my_set

my_set_list=[1,1,1,1,2,2,2,2,2,3,3,3,3,3]

set(my_set_list)



**Boolean** true or false

True

False

type(False)

1>2

1==1

%%writefile myfile.txt
Hello this is sa text file 
this is the second line 
this is the third line 

myfile = open('myfile.txt')

myfile = open('whoops_wrong_file')

pwd

myfile.read()

myfile.read()

myfile.seek(0)

myfile.read()

myfile.seek(0)

myfile.readlines()

myfile.close()

with open('myfile.txt') as my_new_file:
  contents = my_new_file.read()

contents

with open('myfile.txt',mode='w') as my_new_file:
  contents = my_new_file.read()

%%writefile my_newfile.txt
Hello this is  text file 
one is the second line 
two is the third line 

with open('my_newfile.txt', mode='r') as f:
  print(f.read())

with open('my_newfile.txt', mode='a') as f:
 f.write('\n four on fourth line')

with open('my_newfile.txt', mode='r') as f:
  print(f.read())

with open('mabjvhgqvcdsacch.txt', mode='w') as f:
 f.write('i creayted this file')

with open('mabjvhgqvcdsacch.txt', mode='r') as f:
  print(f.read())



comparison operation

1<2

1<2>3

1<2 and 2<3

100 == 1 or 2==2

not 1==1

not 400> 5000



Usage if elif else etc. 

hungry = True
if hungry:
 print ('i want food')

loc = 'Bank'

if loc == 'shop':
 print ('its not a bank go to bank')
elif loc=='Bank':
   print ('its a bank take ur money')
else: 
 print ('get out of here') 

name = 'surya'

if name == 'samar':
 print ('HI samar')
elif name =='funny':
   print ('HI funny')
elif name =='bunny':
  print ('HI bunny')
elif name =='suresh':
   print ('HI Suresh')  
else: 
 print ('HI surya') 

ITERABLE - action for every item
{FOR LOOP} 
mylist[whatever is in ur list/tuple/dictionary]
FOR (a,b) in mylist:
  Print(a,b)

i_list = [1,2,3,4,5,6,7,8,9,10]

for num in i_list:
  print(num)

for num in i_list:
  print('Hello')

for num in i_list:
  if num % 2 == 0:
   print(num)

for num in i_list:
  if num % 2 == 0:
   print(num)
  else:
   print(f'odd no:{num}')

list_sum = 0

for num in i_list:
  list_sum = list_sum + num
  print(list_sum)

list_sum = 0

for num in i_list:
  list_sum = list_sum + num
print(list_sum)

my_string ='HELLO WORLD'

for letter in my_string:
  print(letter)


for _ in 'HELLO WORLD':
  print('cool!')

tup = (1,2,3)

for num in tup:
  print(num)

my_newlist=[(1,2),(3,4),(5,6),(7,8)]
for num in my_newlist:
  print(num)

my_newlist=[(1,2),(3,4),(5,6),(7,8)]
for (a,b) in my_newlist:
  print(a)

d= {'k1':1,'k2':2,'k3':3}
for key,value in d.items():
  print(key)

d= {'k1':1,'k2':2,'k3':3}
for value in d.values():
  print(value)