Shubham SayonSummary: Passing mutable objects as default arguments leads to unexpected outputs because Python initializes the default mutable object only once, not (as you may have expected) each time the function is called. To fix this, initialize the mutable default argument with the None keyword in the argument list and then initialize it within the function. … Read more
Summary: Slicing is a Python concept to extract a subsequence from a string or list—that lies within a start and stop index range. There are two syntactical ways to define a slice. (1) The extended slice notation makes use of a colon : in string_name[start:stop:step]. (2) The slice() constructor defines the index range in string_name[slice(start:stop:step)]. … Read more
Summary: Variables are passed by object reference in Python. Therefore, mutable objects are passed by reference while immutable objects are passed by value in Python. To pass immutable objects by reference you can return and reassign the value to the variable, or pass it inside a dictionary/list, or create a class and use the self … Read more
Summary: One of the following methods can be used to check if a list is empty :- Boolean operator not Explicit check using len() Simple Work Around With [] Using .size() with NumPy Using Exception Handling with iter() method Problem: Given a list; how to check if it is empty? Example: Consider the given list … Read more
Summary: Use one of the following methods to format strings that contain curly braces: Use double curly braces {{}} Use the old string formatting, i.e. the % operator Use the JSON Library Use Template Strings Problem: Given a string literal with curly braces; how to format the string and ensure that the curly braces are … Read more
Summary: To access the index of iterables like lists in Python, use one of the following methods: Use enumerate() function. Use a counter variable with For Loop/While Loop. Use a list comprehension. Use the NumPy library. Use the itertools module. Introduction An index can be considered as the position of an element in an ordered … Read more
Summary: The UnicodeEncodeError generally occurs while encoding a Unicode string into a certain coding. Only a limited number of Unicode characters are mapped to strings. Thus, any character that is not-represented / mapped will cause the encoding to fail and raise UnicodeEncodeError. To avoid this error use the encode(utf-8) and decode(utf-8) functions accordingly in your … Read more
Summary: f-string is more readable and easier to implement than % and .format() string formatting styles. Furthermore, using f-strings is suggested for Python 3.6 and above while .format() is best suited for Python 2.6 and above. Versions prior to Python 2.6 only provide % option for string formatting. In terms of speed, % is the … Read more
Summary: To split a string and keep the delimiters/separators you can use one of the following methods: Problem Formulation 🔏Problem: Given a string in Python; how to split the string and also keep the separators/delimiter? A sequence of one or more characters used to separate two or more parts of a given string or a … Read more
Summary: Since switch-case statements are not a part of Python, you can use one of the following methods to create a switch-case construct in your code : Using a Python Dictionary Creating a Custom Switch Class Using if-elif-else Conditional Statements Using a Lambda Function Problem: Given a selection control switch case scenario in Python; how … Read more
Summary: The key differences between raw_input() and input() functions are the following: raw_input() can be used only in Python 2.x and is obsolete in Python 3.x and above and has been renamed input() In Python 2.x, raw_input() returns a string whereas input() returns result of an evaluation. While in Python 3.x input() returns a string … Read more
Summary: Python output buffering is the process of storing the output of your code in buffer memory. Once the buffer is full, the output gets displayed on the standard output screen. Buffering is enabled by default and you can use one of the following methods to disable it: Execute the Python code with the -u … Read more