Category: Python

One common task you’ll need to accomplish with any language involves merging or combining strings. This process is referred to as concatenation. The best way to describe it is when you take two separate strings – stored by the interpreter – and merge them so that they become one. For instance, one string would be “hello” and the other would be “world.” When you use concatenation to combine them it becomes one string, or “hello world”. This post will describe how to concatenate strings in Python. There are different ways to do that, and we will discuss the most common methods. After, we will explore formatting, and how it works. The Basics: Concatenating Strings Python – Quick Guide Python Programming – Special String Operators Concatenation In Python, there are a few ways to concatenate – or combine – strings. The new string that is created is referred to as a string object. Obviously, this is because everything in Python is an object – which is why Python is an objected-oriented language. In order to merge two strings into a single object, you may use the “+” operator. When writing code, that would look like this: str1 = “Hello” str2 = “World”…

Comments are the statements that are included in the source code but don’t contribute to program logic. A python comment is not executed by the interpreter and it can only be accessed when we have access to the source code. Now the question is that despite the fact that they do not contribute to the program logic, why are the comments included in the source code. In this article, we will try to see why we need comments in python. Let’s dive into it then. How to write comments in Python Comment out a block of code in Python Python Docstrings We use comments to specify the metadata of the source code. When we write any computer program for commercial purposes, We generally include the name of the programmer, the date and time at which the source code was created. Generally, when a program is developed under contract, the conditions for use of the source code and the license and copyright of the source code, and a general description of the program is also included in the source file. To include this information in the source code, we use python comments. Metadata is included in the header comment at the…

A comment is a piece of code that isn’t executed by the compiler or interpreter when the program is executed. Comments can only be read when we have access to the source code. To answer the question about a  good comment/code ratio, we need to first understand the needs that require us to include comments in our source code. Why are comments needed? It is very well known that comments don’t improve the quality of the program. They improve the readability and understanding of the source code. Following are some of the specific reasons for using comments in our source codes. 1. We use comments to specify the license or copyright of the source code. When we write any source code for a commercial purpose, it is customary to specify the name of the author, date and time at which the source code was created. We also specify if the source code is copyrighted or licensed and whether the source code can be used and modified without the permission of authors of the code. Comment out a block of code in Python How to write comments in Python How to create Multiline Comments in Python 2. We use comments to…

A comment is a piece of code that isn’t executed by the compiler or interpreter when the program is executed. Comments can only be read when we have access to the source code. Comments are used to explain the source code and to make the code more readable and understandable. In this article, we will see how to write single line and multi line comments using different methods in python. What is a single line comment in python? Single line comments are those comments which are written without giving a line break or newline in python. A python comment is written by initializing the text of comment with a # and terminates when the end of line is encountered. The following example shows a single line comment in a program where a function is defined to add a number and its square to a python dictionary as key value pair. #This is a single line comment in python def add_square_to_dict(x,mydict): a=x*x mydict[str(x)]=a return mydict We can also add a single line comment after another statement. #This is a single line comment in python print(“Pythonforbeginners.com”) #This is also a python comment How to write comments in Python Comment out a block of code in Python How to…

We often need to comment out block of codes in python while testing or debugging the code. When a block is turned into a python comment, it doesn’t contribute in output of the program and helps to determine which function or block is generating error in the program. In this article, we will look at some shortcut to comment out multiple lines of code at once in different python IDEs. Lets see examples for each IDE one by one. Shortcut to comment out multiple lines in Spyder In spyder python IDE, we can comment a single line of code by selecting the line and then using the key combination ctrl+1 . This will turn the selected single line to a comment as shown below. The function given in the example adds a number and its square to a python dictionary as a key-value pair. print(“This line will be commented out.”) def add_square_to_dict(x,mydict): a=x*x mydict[str(x)]=a return mydict After pressing ctrl+1: #print(“This line will be commented out.”) def add_square_to_dict(x,mydict): a=x*x mydict[str(x)]=a return mydict The shortcut to comment out multiple lines of code in spyder IDE is to first select all the lines which need to be commented out and then the key combination ctrl+4 is pressed.…

Comments are used to enhance readability and understandability of source code by providing proper information about the code. Comments are not executed by an interpreter or compiler and they are used in the code only for assistance of the programmer. In this article, we will understand how to create multiline comments in python. What is a multiline comment in python? As we can see in the name itself, a multiline comment is a python comment which expands to multiple lines i.e. multiline comments are those comments which expand to two or more lines in the source code. Theoretically speaking, there is no syntax for multiline comments in python but we can implement multi line comment using single line comment or triple quoted strings. We will look at both methods to implement multiline comments one by one. Comment out a block of code in Python How to write comments in Python Difference between Comments and Docstrings in Python How to create multiline comments in python using # symbol? As we know that single line comment in python are implemented by adding # symbol before the comment and it terminates whenever a line break occurs, we can put a # symbol at the start of each…

Comments in python are very handy in increasing the readability and maintainability of code. Generally we use comments to describe functions and class descriptions, for documentation purposes or to explain why a statement has been written in the source code but there may be a situation that we need to explain why we have included certain data in a dictionary or a list. In this article, we will see the basic functioning of python dictionaries and will try to understand how we can add comment inside a python dictionary. Convert Dictionary Values List Python | How to Convert Dictionary Values to a List in Python Python Programming – Python Dictionary Python Programming – Dictionaries Working of a python dictionary In Python, dictionaries are data structures that are used to store data in the form of key and value pairs.A python dictionary is defined using curly braces and key and value pairs are inserted in the dictionary separated by colon “:” while initializing or may be added after initialization using assignment statement. A key-value pair in a python dictionary is called an item. The simplest way to initialize a dictionary is as follows: website_details={“name”:”Pyhton For Beginners”, “domain”:”pythonforbeginners.com” } print(“dictionary is:”) print(website_details) print(“Keys in…

Comments are used to increase the readability and understandability of the source code. A python comment may be a single line comment or a multiline comment written using single line comments or multiline string constants. Document strings or docstrings are also multiline string constants in python but they have very specific properties unlike python comment. In this article we will look at the differences between comments and docstrings in python. Declaration of comments in python Single line comments in python are declared using a # sign as follows. #This is a single line comment. Python does not primarily have multiline comments but we can write multiline comments in python using multiple single line comments as follows. The function given in the example adds a number and its square to a python dictionary as key value pair. #This is a multiline comment #written using single line comments def add_square_to_dict(x,mydict): a=x*x mydict[str(x)]=a return mydict We can also implement multiline comments in python using multiline string constants as follows. Here the multiline string is declared but isn’t assigned to any variable due to which no memory is allocated for it and it works just like a comment. “””This is a multiline comment written using multiline strings…

Overview of the Collections Module The Collections module implements high-performance container datatypes (beyond the built-in types list, dict and tuple) and contains many useful data structures that you can use to store information in memory. This article will be about the Counter object. Counter A Counter is a container that tracks how many times equivalent values are added. It can be used to implement the same algorithms for which other languages commonly use bag or multiset data structures. Show most requested URL in apache Python generators and the yield keyword How to Check for Anagrams In Python Importing the module Import collections makes the stuff in collections available as: collections.something import collections Since we are only going to use the Counter, we can simply do this: from collections import Counter Initializing Counter supports three forms of initialization. Its constructor can be called with a sequence of items (iterable), a dictionary containing keys and counts (mapping, or using keyword arguments mapping string names to counts (keyword args). import collections print collections.Counter([‘a’, ‘b’, ‘c’, ‘a’, ‘b’, ‘b’]) print collections.Counter({‘a’:2, ‘b’:3, ‘c’:1}) print collections.Counter(a=2, b=3, c=1) The results of all three forms of initialization are the same. $ python collections_counter_init.py Counter({‘b’: 3, ‘a’:…

Python includes several modules in the standard library for working with emails and email servers. smtplib Overview The smtplib module defines an SMTP client session object that can be used to send mail to any Internet machine with an SMTP or ESMTP listener daemon. SMTP stands for Simple Mail Transfer Protocol. The smtplib modules is useful for communicating with mail servers to send mail. Sending mail is done with Python’s smtplib using an SMTP server. Actual usage varies depending on complexity of the email and settings of the email server, the instructions here are based on sending email through Gmail. Sending Emails Using Google Python Code Examples How to use FTP in Python smtplib Usage This example is taken from this post at wikibooks.org “””The first step is to create an SMTP object, each object is used for connection with one server.””” import smtplib server = smtplib.SMTP(‘smtp.gmail.com’, 587) #Next, log in to the server server.login(“youremailusername”, “password”) #Send the mail msg = ” Hello!” # The /n separates the message from the headers server.sendmail(“you@gmail.com”, “target@example.com”, msg) To include a From, To and Subject headers, we should use the email package, since smtplib does not modify the contents or headers at all. Email Package…