LIST

• Lists are mutable i.e they can be edited
• Lists are slower than tuples.
• Syntax: list_1 = [10, ‘Chelsea’, 20]

TUPLES

• Tuples are immutable (tuples are lists which can’t be edited)
• Tuples are faster than list.
• Syntax: tup_1 = (10, ‘Chelsea’ , 20)

Slicing is used to access parts of sequences like lists, tuples, and strings. The syntax of slicing is-[start:end:step]. The step can be omitted as well. When we write [start:end] this returns all the elements of the sequence from the start (inclusive) till the end-1 element. If the start or end element is negative i, it means the ith element from the end. The step indicates the jump or how many elements have to be skipped. Eg. if there is a list- [1,2,3,4,5,6,7,8]. Then [-1:2:2] will return elements starting from the last element till the third element by printing every second element.i.e. [8,6,4].

The dataframes in python can be combined in the following ways-
1. Concatenating them by stacking the 2 dataframes vertically.
2. Concatenating them by stacking the 2 dataframes horizontally.
3. Combining them on a common column. This is referred to as joining.
The concat() function is used to concatenate two dataframes. Its syntax is- pd.concat([dataframe1, dataframe2]).
Dataframes are joined together on a common column called a key. When we combine all the rows in dataframe it is union and the join used is outer join. While, when we combine the common rows or intersection, the join used is the inner join. Its syntax is- pd.concat([dataframe1, dataframe2], axis=’axis’, join=’type_of_join)

• Global Variables:
  Variables declared outside a function or in global space are called global variables. These variables can be accessed by any function in the program.
• Local Variables:
  Any variable declared inside a function is known as a local variable. This variable is present in the local space and not in the global space.
  
  

A function is a block of code which is executed only when it is called. To define a Python function the def keyword is used.

Consider the example shown below:
1
2
3
4 from random import shuffle
x = [‘Keep’, ‘The’, ‘Blue’, ‘Flag’, ‘Flying’, ‘High’]
shuffle(x)
print(x)
The output of the following code is as below.
[‘Flying’, ‘Keep’, ‘Blue’, ‘High’, ‘The’, ‘Flag’]

• Python libraries are a collection of Python packages. Some of the majorly used python libraries are – Numpy, Pandas, Matplotlib, Scikit-learn and many more.

Class in Python is created using the class keyword.
Example:
1
2
3
4
5 class Employee:
def __init__(self, name):
self.name = name
E1=Employee(“abc”)
print(E1.name)
Output: abc

1
2
3
4 def pyfunc(r):
for x in range(r):
print(‘ ‘*(r-x-1)+’*’*(2*x+1))
pyfunc(9)

Output:

*
***
*****
*******
*********
***********
*************
***************
*****************

1
2
3
4
5
6
7
8
9
10 a=int(input(“enter number”))
if a=1:
for x in range(2,a):
if(a%x)==0:
print(“not prime”)
break
else:
print(“Prime”)
else:
print(“not prime”)

Output:
enter number 3
Prime