What is Numpy library in python? | python crash course_01

What is the Numpy library in python?

 Hello everyone, welcome to my python crash course. In the previous blog post, I released the python syllabus so it's time to start the tutorial. Let's start:

Numpy

What is a Python NumPy?

Numpy is Python package that stands for ‘Numerical Python’. It is the core library for scientific computing, which contain a powerful n-dimensional array object, provide tool for integrating C, C++, etc. It is also useful in linear algebra, random number capability. Numpy array can also used as an efficient multi-dimensional container for generic data. Now, let me tell you what exactly is python Numpy array.

NumPy Array: Numpy array is powerful N-dimensional array object which is in the form of row and column. We can initialize numpy arrays from nested Python lists and access it element. In order to perform these numpy operation, the next question which will come in your mind is:

How do I install NumPy?

To install Python Numpy, go to your command prompt and type “pip install Numpy”. Once the installation is completed, go to your IDE and simply import it by typing: “Import Numpy as np”
Moving ahead in python numpy tutorials, let us understand what exactly is a multi-dimensional Numpy array.

Trigonometric Function

Numpy has standard trigonometric function which return trigonometric ratios for a given angle in radian.

Example

import numpy as np 
a = np.array([0,30,45,60,90]) 

print 'Sine of different angles:' 
# Convert to radian by multiplying with pi/180 
print np.sin(a*np.pi/180) 
print '\n'  

print 'Cosine values for angles in array:' 
print np.cos(a*np.pi/180) 
print '\n'  

print 'Tangent values for given angles:' 
print np.tan(a*np.pi/180) 

output is:

Sine of different angles:
[ 0.          0.5         0.70710678  0.8660254   1.        ]

Cosine values for angle in array:
[  1.00000000e+00   8.66025404e-01   7.07106781e-01   5.00000000e-01
   6.12323400e-17]                                                            

Tangent values for given angle:
[  0.00000000e+00   5.77350269e-01   1.00000000e+00   1.73205081e+00
   1.63312394e+16]

for detail information please open below  drive link:
https://drive.google.com/open?id=1tiE_cc8O8yRBYNKrSnhd8TO2mdZKdHtW
FOR DETAILED PLEASE CLICK BELOW:

CLICK HERE 
(NOTE: If any question then comment)
                                                          BEST OF LUCK!!!!!

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Print first n numbers made up of some particular digits | Queue Application | Python

Prerequisite: Stacks and Queues using List | Data Structures | Python | Castor Classes https://www.youtube.com/watch?v=bMVBW... Python for beginners: https://www.youtube.com/watch?v=egq7Z...

Code:
x=int(input('Enter the first digit:'));
y=int(input('Enter the second digit:'));
l=[];
q=[];
n=int(input("How many numbers you want?"));
i=0;
q.append(str(x));
q.append(str(y));
while(i<n):
    es=q.pop(0);
    l.append(int(es));
    ex=es+str(x);
    q.append(ex);
    ey=es+str(y);
    q.append(ey);
    i=i+1;
print(l)

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IN operator as a shorthand for multiple OR conditions in Python

Prerequisite: List membership Testing using in | Part 8 | Python | Castor Classes https://www.youtube.com/watch?v=ggmBT... Python for beginners: https://www.youtube.com/watch?v=egq7Z...

Telegram: https://t.me/clcoding_python https://www.facebook.com/pirawenpython/ https://www.facebook.com/groups/piraw...

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what is python? | overview about python language

Hello everyone, welcome to my blog post, today we have to start python crash course so first upon required to know the basics of this programming language hence let's start.

INTRODUCTION TO PYTHON:

(Befor the starting the section please read the this post: CLICK HERE)

Python was conceived in the late 1980s as a successor to the ABC language. Python 2.0, released in 2000, introduced features like list comprenstion and a garbage collection system capable of collecting reference cycle. Python 3.0, released in 2008, was a major revision of the language that is not completely backward, and much Python 2 code does not run unmodified on Python 3.

The Python 2 language was officially discontinued in 2020 (first planned for 2015), and "Python 2.7.18 is the last Python 2.7 release and therefore the last Python 2 release. No more security patches or other improvements will be released for it. With Python 2's end of life, only Python 3.5.x and later are supported.

Python is a general purpose and high level programming language. You can use Python for developing desktop GUI applications, websites and web applications. Also, Python, as a high level programming language, allows you to focus on core functionality of the application by taking care of common programming tasks.

Python is an object-oriented programming language created by Guido Rossum in 1989. It is ideally designed for rapid prototyping of complex applications. Python programming is widely used in Artificial Intelligence, Natural Language Generation, Neural Networks and other advanced fields of Computer Science.

(Note: If you want to read more introduction then click on Read more)
                                            BEST OF LUCK!!!!

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Evaluate Reverse Polish Notation | Python

Problem Statement:
Evaluate the value of an arithmetic expression in Reverse Polish Notation.

Valid operators are +, -, *, /. Each operand may be an integer or another expression.

Note:

The division between two integers should truncate toward zero.
The given RPN expression is always valid. That means the expression would always evaluate to a result and there won't be any divide by zero operation.
Example 1:

Input: ["2", "1", "+", "3", "*"]
Output: 9
Explanation: ((2 + 1) * 3) = 9
Example 2:

Input: ["4", "13", "5", "/", "+"]
Output: 6
Explanation: (4 + (13 / 5)) = 6
Example 3:

Input: ["10", "6", "9", "3", "+", "-11", "*", "/", "*", "17", "+", "5", "+"]
Output: 22
Explanation:
  ((10 * (6 / ((9 + 3) * -11))) + 17) + 5
= ((10 * (6 / (12 * -11))) + 17) + 5
= ((10 * (6 / -132)) + 17) + 5
= ((10 * 0) + 17) + 5
= (0 + 17) + 5
= 17 + 5
= 22

Python for beginners: https://www.youtube.com/watch?v=egq7Z...

Code:
class Solution:
    def evalRPN(self, tokens: List[str]) -> int:
        l=[];
        for i in tokens:
            if(i=='+' or i=='-' or i=='*' or i=='/'):
                a=l.pop(-1);
                b=l.pop(-1);
                g=b+i+a;
                w=eval(g);
                e=int(w);
                l.append(str(e));
            else:
                l.append(i);
        return int(l[0]);

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if – if else – if else if ladder in C#

C#  IF Statement :

Syntax :

if(condition)
{
//code to be executed
}

Prog : Write a program to test whether a number is even or not

C#  IF-ELSE Statement :

Syntax :

if(Condition)
{
// code to be executed
}else
{
//Code if condition is false
}

Prog : Write a program to test whether a number is even or not

C# IF - ELSE - IF LADDER Statement :

Syntax :

if(Condition1)
{
//code to be executed
}else if (Condition2)
{
//code to be executed
}
else 
{
//Code when all the condition are false
}


Program : Write a program to print Grade of Student as per Marks.

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Mathematical functions | Python

For more detail on math module , check the below link: https://docs.python.org/3/library/mat... Relationship between number of digits of a number and it's logarithm: https://math.stackexchange.com/questi... Python for beginners: https://www.youtube.com/watch?v=egq7Z...

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Plus One | Python

Python for beginners: https://www.youtube.com/watch?v=egq7Z...

Code:

class Solution:

    def plusOne(self, digits: List[int]) -> List[int]:

        g="";

        for i in digits:

            g+=str(i);

        e=int(g);

        e=e+1;

        g=str(e);

        w=list(g);

        output=[];

        for i in w:

            output.append(int(i));

        return output;

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Majority Element | Python

Check the problem statement here:
https://leetcode.com/problems/majorit... Python for beginners: https://www.youtube.com/watch?v=egq7Z...

Code:


class Solution:
    def majorityElement(self, nums: List[int]) -> int:
        nums.sort();
        return nums[len(nums)//2];

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Max Consecutive Ones | Python

Check the problem statement here: Max Consecutive Ones https://leetcode.com/problems/max-con... Python for beginners: https://www.youtube.com/watch?v=egq7Z...
Code: class Solution: def findMaxConsecutiveOnes(self, nums: List[int]) -> int: g=""; for i in nums: g=g+str(i); e=g.split('0'); max=0; for i in e: if(max<len(i)): max=len(i); return max;

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eval | Python

Explore more about eval here: https://docs.python.org/3/library/fun... https://towardsdatascience.com/python... To convert the string into a numerical value use the function eval(string ) Test the following : a=eval(input()); type(a) Give a as 16 & check whether eval is converting input to a proper numeric datatype or not. Give a as 16.32 & check whether eval is converting a to proper numeric datatype or not. Python for beginners: https://www.youtube.com/watch?v=egq7Z...

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The continue Statement | Python

For more detail explanation, check the below link: https://www.tutorialspoint.com/python... Python for beginners: https://www.youtube.com/watch?v=egq7Z... Web 🌐http://www.clcoding.com/ Telegram: https://t.me/clcoding_python https://www.facebook.com/pirawenpython/ https://www.facebook.com/groups/piraw...

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end parameter in print() | Python

Python for beginners: https://www.youtube.com/watch?v=egq7Z... Web 🌐http://www.clcoding.com/ Telegram: https://t.me/clcoding_python https://www.facebook.com/pirawenpython/ https://www.facebook.com/groups/piraw...

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Handling Exceptions | Python

You can catch an exception by implementing the try—except construct. This construct is broken into 2 major parts: • try block. The try block indicates the code which is to be monitored for the exceptions listed in the except expressions. • except clause. You can use an optional except clause to indicate what to do when certain classes of exception/error occur (e.g. resolve the problem or generate a warning message). There can be any number of except clauses in sequence checking for different types of error/exceptions. For more detail explanation , check this below link: https://docs.python.org/3/tutorial/er... Python for beginners: https://www.youtube.com/watch?v=egq7Z...

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Mathematical Operations on Set | Python

Prerequisite: Set | Python | Castor Classes https://www.youtube.com/watch?v=DNlWy... Python for beginners: https://www.youtube.com/watch?v=egq7Z... Web 🌐http://www.clcoding.com/ Telegram: https://t.me/clcoding_python https://www.facebook.com/pirawenpython/ https://www.facebook.com/groups/piraw...

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Nth term of GP | Python

Code: a=int(input('Enter the first term')); b=int(input('Enter the second term')); N=int(input('Enter the n value')); # 2 4 8 16 32 r=b/a; s=a*r**(N-1); print(s); Prerequisite: Power of a number | Python | Castor Classes https://www.youtube.com/watch?v=omFAv... Python for beginners: https://www.youtube.com/watch?v=egq7Z...

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Is Subsequence | Python

Prerequisite: String in Python | Part 2.3 | Castor Classes https://www.youtube.com/watch?v=65z1V... Check the problem statement here: https://leetcode.com/problems/is-subs... Python for beginners: https://www.youtube.com/watch?v=egq7Z...

Code:


class Solution:
    def isSubsequence(self, s: str, t: str) -> bool:
        g=0;
        for i in s:
            if(i in t):
                rs=t.index(i);
                t=t[rs+1:];
            else:
                g+=1;
        if(g==0):
            return True;
        else:
            return False;

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Set | Python

Python for beginners: https://www.youtube.com/watch?v=egq7Z... Web 🌐http://www.clcoding.com/ Telegram: https://t.me/clcoding_python https://www.facebook.com/pirawenpython/ https://www.facebook.com/groups/piraw...

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help & tab completion | Python

Topics discussed in this video: a)Getting help in Python & some important methods related to String-- 1).isalpha() 2).isalnum() 3).islower() 4).isupper() b)tab completion in Python Python for beginners: https://www.youtube.com/watch?v=egq7Z...

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what are the difference between LIST , TUPLE and SET in python ?

The tuple, list, set, dictionary are trying to solve the most important problems in programming, called, storage of data and retrieval of stored data in a way that is both easy to use, to code and to read for the programmers.
The big problems are:
- space availability
- insertion
- searching by value or position
- updating
- make the operations faster for big/huge data sets
Tuple:
When you only store data that you aren't changing and don't need to do search by value as you know the position.
List:
When you store data that you changing, inserting if fast and don't need to do search/update by value as you know the position
Set:
When you store data that changes from times to time, but most importantly you need very fast search by value as you don't know position then you use sets.The search is very fast as the set is indexed in memory and fast binary search used. Inserting and deletion is slow.
Dictionary:
When you need fast search, data doesn't change often, few updates and inserts. Is just advanced set where you store a group of key and value and search by the key.

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Largest Number At Least Twice of Others | Python

Python for beginners: https://www.youtube.com/watch?v=egq7Z...

Code:

class Solution:

    def dominantIndex(self, nums: List[int]) -> int:

        f=max(nums);

        rs=nums.index(f);

        u=[];

        g=0;

        for i in nums:

            if(i!=f):

                u.append(i);

        if(len(u)!=0):

            g=max(u);

        if(f>=2*g):

            return rs;

        else:

            return -1;

Telegram: https://t.me/clcoding_python 
https://www.facebook.com/pirawenpython/ 
https://www.facebook.com/groups/piraw...

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