python tutorial - Python django interview questions - learn python - python programming
python interview questions :71
Vector of pairs in python?
- It is storing in a dictionary (Hashmap)
- This gives you a better representation. If you are tight on space, then you can store it as either of the following:
python interview questions :72
Converting a Python dict to Octave equivalent?
python interview questions :73
How to retrieve data from a table in MySQL database through Python code?
- import MySQLdb module as : import MySQLdb
- establish a connection to the database.
- initialize the cursor variable upon the established connection: c1 = db.cursor()
- retrieve the information by defining a required query string. s = “Select * from dept”
- fetch the data using fetch() methods and print it. data = c1.fetch(s)
- close the database connection. db.close()
python interview questions :74
Explain about ODBC and Python ?
- ODBC (“Open Database Connectivity) API standard allows the connections with any database that supports the interface, such as PostgreSQL database or Microsoft Access in a transparent manner
- There are 3 ODBC modules for Python:
- PythonWin ODBC module - limited development
- mxODBC - commercial product
- pyodbc - it is an open source Python package.
python interview questions :75
How would you define a protected member in a Python class?
- All the members of a class in Python are public by default. You don’t need to define an access specifier for members of class.
- By adding ‘_’ as a prefix to the member of a class, by convetion you are telling others please don’t this object, if you are not a subclass the respective class.
python interview questions :76
How do you remove duplicates from a list?
- sort the list
- scan the list from the end.
- while scanning from right-to-left, delete all the duplicate elements from the list
python interview questions :77
Differentiate between append() and extend() methods. ?
- Both append() and extend() methods are the methods of list. These methods a re used to add the elements at the end of the list.
- append(element) - adds the given element at the end of the list which has called this method.
- extend(another-list) - adds the elements of another-list at the end of the list which is called the extend method.
python interview questions :78
Name few Python Web Frameworks for developing web applications?
- There are various web frameworks provided by Python. They are
- web2py - it is the simplest of all the web frameworks used for developing web applications.
- cherryPy - it is a Python-based Object oriented Web framework.
- Flask - it is a Python-based micro-framework for designing and developing web applications.
python interview questions :79
How do you check the file existence and their types in Python?
- os.path.exists() - use this method to check for the existence of a file. It returns True if the file exists, false otherwise. Eg: import os; os.path.exists(‘/etc/hosts’)
- os.path.isfile() - this method is used to check whether the give path references a file or not. It returns True if the path references to a file, else it returns false. Eg: import os; os.path.isfile(‘/etc/hosts’)
- os.path.isdir() - this method is used to check whether the give path references a directory or not. It returns True if the path references to a directory, else it returns false. Eg: import os; os.path.isfile(‘/etc/hosts’)
- os.path.getsize() - returns the size of the given file
- os.path.getmtime() - returns the timestamp of the given path.
python interview questions :80
Name few methods that are used to implement Functionally Oriented Programming in Python?
- Python supports methods (called iterators in Python3), such as filter(), map(), and reduce(), that are very useful when you need to iterate over the items in a list, create a dictionary, or extract a subset of a list.
- filter() - enables you to extract a subset of values based on conditional logic.
- map() - it is a built-in function that applies the function to each item in an iterable.
- reduce() - repeatedly performs a pair-wise reduction on a sequence until a single value is computed.
- The list1 and list3 are hence operating on the same default list, whereas list2 is running on a separate list that it has created on its own (by passing an empty list as the value of the list parameter).
- The definition of the extendList function can get changed in the following manner.
- With this revised implementation, the output would be: