To test a Python program, use the unittest module in Pygthon. The doctest and unittest modules or third-party test frameworks can be used to construct exhaustive test suites that exercise every line of code in a module. The doctest module The doctest module searches for pieces of text that look like interactive Python sessions, and then executes those sessions to verify that they work exactly as shown. The unittest module The unittest module supports test automation, sharing of setup and shutdown code for tests, aggregation of tests into collections, and independence of the tests from the reporting framework. Before moving ... Read More

Python allow commas at the end of lists and tuples. It is optional and makes the items more readable and you can reorder the items without getting any error. You don’t need to remember again and again to add a trailing comma after every item, if you add a comma in the end. Let’s see some examples − Lists Example In this example, we will add a trailing comma in the List and there won’t be any error − # Creating a List myList = ["Jacob", "Harry", "Mark", "Anthony", ] # Displaying the List print("List = ", myList) ... Read More

The colon is required for all these keywords, if, while, def, class, etc in Python to enhance readability. The colon makes it easier for editors with syntax highlighting i.e. they can look for colons to decide when indentation needs to be increased. Let’s see an example of an if statement − if a == b print(a) And, if a == b: print(a) The 2nd example is easier to read, understand and indent. This makes the usage of colon quite popular. The def and if keyword example We have an if statement in ... Read More

Python definitely has a with statement. It wraps the execution of a block, calling code on the entrance and exit from the block. Some languages have a construct like the below − with obj: a = 1 total = total + 1 The above a = 1 is equivalent to the following − obj.a = 1 And, total = total + 1 is equivalent to − obj.total = obj.total + 1 Programming Languages use static or dynamic types. Static Type Static refers to the execution of a program where type of object is ... Read More

The r in r-strings means raw strings. String literals may optionally be prefixed with a letter 'r' or 'R'; such strings are called raw strings and use different rules for interpreting backslash escape sequences. When an 'r' or 'R' prefix is present, a character following a backslash is included in the string without change, and all backslashes are left in the string. For example, the string literal r"" consists of two characters − a backslash and a lowercase 'n'. String quotes can be escaped with a backslash, but the backslash remains in the string; for example, r""" is ... Read More

Yes, there is no goto statement in Python. Let us first understand what is a goto in C Language. However, the usage of goto is also discouraged in C. The goto statement in C programming provides an unconditional jump from the 'goto' to a labelled statement in the same function. Following is the syntax − goto label; .. . label: statement; Example Let us now see a C program for goto − #include int main () { int a = 10; LOOP:do { if( a == 15) { /* skip the iteration */ a = a + 1; goto LOOP; } printf("a = %d", a); a++; }while( a

Let us first see what is an interface spec. The interface spec is an interface specification for a module provided by programming languages such as C++ and Java. It describes the prototypes for the methods and functions of the module. The abc module The abc module introduced in Python 2.6 to define Abstract Base Classes (ABCs). Use the isinstance() and issubclass() to check whether an instance or a class implements a particular Abstract Base Class. With that, the collections.abc module defines a set of useful ABCs such as Iterable, Container, and MutableMapping. The collections module has classes that derive from ... Read More

Example In this example, let’s first see the usage of list.sort() before moving further. Here, we have created a List and sorted in Ascending order using the sort() method − # Creating a List myList = ["Jacob", "Harry", "Mark", "Anthony"] # Displaying the List print("List = ", myList) # Sort the Lists in Ascending Order myList.sort() # Display the sorted List print("Sort (Ascending Order) = ", myList) Output List = ['Jacob', 'Harry', 'Mark', 'Anthony'] Sort (Ascending Order) = ['Anthony', 'Harry', 'Jacob', 'Mark'] Where performance matters more, making a copy of the list just ... Read More

In Python to display calendar, you need to import calendar module, it provides various functions to handle operations related to calendar, and also includes printing a text calendar for a month . Calendar Module The calendar module in python provides various functions and classes to perform date-related operations. To print a calendar in Python, we import the calendar module, which will import all module classes. Key Features Some of the features provided by Calendar module are as follows: Calendar Functions: To generate HTML or text format ... Read More

Regular expressions, often known as RegEx, are a string of characters corresponding to letters, words, or character patterns in text strings. It implies that you may use regular expressions to match and retrieve any string pattern from the text. Search and replace procedures benefit from the usage of regular expressions. The most common application is searching for a substring that matches a pattern and substituting something else. What are whitespace characters? "Whitespace" refers to any letter or set of characters representing either horizontal or vertical space. Using regular expressions, the metacharacter “\s” matches whitespace characters in python. Algorithm ... Read More