Python Articles - Page 209 of 829

We will see here how to reverse the rows of a Pandas Dataframe. Pandas is an open-source Python Library providing high-performance data manipulation and analysis tool using its powerful data structures. A Data frame is a two-dimensional data structure, i.e., data is aligned in a tabular fashion in rows and columns. Reverse the rows of a Pandas Data Frame using indexing Example In this example, we will reverse the rows of a dataframe using [::-1] − import pandas as pd # Create a Dictionary dct = {'Rank':[1, 2, 3, 4, 5], 'Points':[100, 87, 80, 70, 50]} # Create a ... Read More

Pandas is an open-source Python Library providing high-performance data manipulation and analysis tool using its powerful data structures. The name Pandas is derived from the word Panel Data – an Econometrics from Multidimensional data. Series is a one-dimensional labelled array capable of holding data of any type i.e. integer, string, float, python objects, etc). The axis labels are collectively called index. To create a series, at first install the pandas library. We use pip to install any library in Python − pip install pandas Create a Pandas Series from a List Example We will create a series from a ... Read More

In Python, if you want to copy object, the assignment operator won’t fulfil the purpose. It creates bindings between a target and an object i.e., it never creates a new object. It only creates a new variable sharing the reference of the original object. To fix this, the copy module is provided. This module has generic shallow and deep copy operations. Shallow Copy A shallow copy constructs a new compound object and then inserts references into it to the objects found in the original. It uses the following method to copy objects  − copy.copy(x) Return a shallow copy of x. ... Read More

The arrays in Python are ndarray objects. The matrix objects are strictly 2-dimensional whereas the ndarray objects can be multi-dimensional. To create arrays in Python, use the Numpy library. Matrices in Python Matrix is a special case of two-dimensional array where each data element is of strictly same size. Matrices are a key data structure for many mathematical and scientific calculations. Every matrix is also a two-dimensional array but not vice versa. Matrix objects are a subclass of ndarray, so they inherit all the attributes and methods of ndarrays. Example Create a Matrix and Display from numpy import * ... Read More

We will display the contents of a text file in reverse order. For that, let us first create a text file amit.txt with the following content  Display the contents of a text file in Reverse Order with Slicing Example Let us now read the contents of the above file in reverse order − # The file to be read with open("amit.txt", "r") as myfile: my_data = myfile.read() # Reversing the data by passing -1 for [start: end: step] rev_data = my_data[::-1] # Displaying the reversed data print("Reversed data = ", rev_data) Output Reversed ... Read More

Let us understand what is Del and Remove() in a Python List before moving towards the difference. Del Keyword in Python List The del keyword in Python is used to remove an element or multiple elements from a List. We can also remove all the elements i.e. delete the entire list. Example Delete an element from a Python List using the del keyword #Create a List myList = ["Toyota", "Benz", "Audi", "Bentley"] print("List = ", myList) # Delete a single element del myList[2] print("Updated List = ", myList) Output List = ['Toyota', 'Benz', 'Audi', 'Bentley'] Updated ... Read More

Python Sequences includes Strings, Lists, Tuples, etc. We can merge elements of a Python sequence using different ways. Merge Elements in a Python List Example The join() method is used to merge elements − # List myList = ['H', 'O', 'W', 'A', 'R', 'E', 'Y', 'O', 'U'] # Display the List print ("List = " + str(myList)) # Merge items using join() myList[0 : 3] = [''.join(myList[0 : 3])] # Displaying the Result print ("Result = " + str(myList)) Output List = ['H', 'O', 'W', 'A', 'R', 'E', 'Y', 'O', 'U'] Result = ['HOW', 'A', 'R', ... Read More

In Python, the // is the double slash operator i.e. Floor Divison. The // operator is used to perform division that rounds the result down to the nearest integer. The usage of the // operator is quite easy. We will also compare the results with single slash division. Let us first see the syntax: Syntax of // (double slash) Operator The a and b are 1st and 2nd number: a // b Example of // (double slash) Operator Let us now see an example to implement the double slash operator in Python - a = 37 b = 11 ... Read More

In this article, we will learn about the advantages of a Numpy array with a Nested List in Python. The Numpy array definitely has advantages over a Nested. Let’s see the reasons − The array in Numpy executes faster than a Nested List. A Nested List consumes more memory than a Nested List. Numpy Array NumPy is an N-dimensional array type called ndarray. It describes the collection of items of the same type. Items in the collection can be accessed using a zero-based index. Every item in an ndarray takes the same size of block in the memory. ... Read More

In this article, we will explain PEP8 and its uses in python. Also, we will see its advantages while coding. What is PEP8? PEP is an abbreviation for Python Enterprise Proposal. Writing code with good logic is a crucial aspect of programming, but many other important elements can affect the quality of the code. The developer's coding style makes the code more reliable, and every developer should remember that Python rigidly follows the string's order and format. A good coding style makes the code more readable. The code is simplified for the end user PEP 8 is a document that ... Read More