LISTS:
Python is a mostly used popular language to develop webpage or
software. This article helps how to
Create
Access
elements
Remove
elements List is
Ordered
: order of element insertion are maintained
Heterogeneous
: contain data of different datatypes
Changeable/Mutable
: elements can be modified
Duplicate
: List allows to store duplicate values
Create
Using
list() constructor : values inside the list() separated by coma
(,) l1=list((11,12,13,14,15))
print(l1)
#It will
print [11,12,13,14,15]
Using
( [] ) : enclosing the items inside the [ ]
Access
Using
slicing operator [ m:n ]
Add
l1 = [11,12,13,14,15]
append(n)
|
add at the end l1.append(16) #It will
print [11,12,13,14,15,16]
|
insert(p,n)
|
add at the specific position #insert 33 at
position 3 l1.insert(3,33) #It will print
[11,12,13,33,,14,15]
|
extend(l1)
|
add another list at the end of the list
l1.extend([10,9,8]) #It will print
[11,12,13,14,15,10,9,8]
|
Remove
l1 = [11,12,13,14]
remove(value)
|
Remove first occurrence of element(n)
l1.remove(12) #It will print [11,13,14]
|
pop(index)
|
1. Removes and returns the value of passing index 2.
Remove last elements if index is not passed
l1.pop(2) #It will print [11,12,14]
l1.pop() #It will print [11,12]
|
clear()
|
Remove all elements Output empty
list l1.clear() #It will print []
|
del listname
|
Delete the entire list del l1 #delete
entire list
|
DICTIONARY:
In
python dictionary is a built-in data types.
It
defines one-to-one relationship between keys and values.
Dictionary contains keys : value pair.
Dictionary are indexed by keys.
Dictionary defined with curly braces { }.
Dictionary Items
Ordered
: ordered of item insertion are maintained
Changeable/Mutable
: items can modified
Not
Duplicate : dictionary cannot have two items with the same key
Create
sd={ "Country":"India", "Capital":"Delhi", "PM":"Modi" }
print(sd)
OUTPUT:
{'Country': 'India' , 'Capital': 'Delhi', 'PM': 'Modi'}
Print the value of the dictionary
sd={ "Country": "India", "Capital": "Delhi", "PM": "Modi" }
print
sd[Country]
print sd[Capital]
print sd[PM]
OUTPUT:
India
Delhi
Modi
Duplicate value will overwrite
sd={ "Country": "India", "Country": "Japan" "Capital": "Delhi",
"PM": "Modi" }
print(sd)
OUTPUT:
{'Country': 'Japan' , 'Capital': 'Delhi', 'PM': 'Modi}
Dictionary Length
print(len(sd))
OUTPUT:
3
Data Types
sd={ "Country": "India", "Capital": "Delhi", "PM": "Modi",
"Pollution": "True", "States": ["West Bengal", "Bihar",
"Punjab"........] }
print(sd)
OUTPUT:
{'Country': 'India', 'Capital': 'Delhi', 'PM': 'Modi', 'Pollution': 'True', 'States': ['West Bengal', 'Bihar', 'Punjab'......]}
Type()
print(type(dict))
OUTPUT:
class 'dict'
Dict() Constructor
sd=dict(Country= "India", Capital= "Delhi", PM="Modi")
print(sd)
OUTPUT:
{'Country': 'India' , 'Capital': 'Delhi', 'PM': 'Modi'}
With lists and dictionaries, you can do more with less code in Python.