Python Programming Functions

Python Functions

• round(45.8) returns the rounded value of 45.8
• round(6352.898,2,5) is not a valid syntax for the round function
• round() without arguments is not a valid function call
• round(7463.123,2,1) is not a valid syntax for the round function

Python Data Types

• The id function returns an integer value that is unique for each object
• In Python, you do not specify types, it is directly interpreted by the compiler
• The // operator is used for integer division in Python 3.0
• The int(..) function is used to type cast a value to an integer

Python Operations

• The * operator is used for string repetition, not mathematical multiplication
• The + operator is used for string concatenation, not mathematical addition
• The / operator is used for float division, not integer division

Python Syntax

• Indentation is required for Python codes to be executed correctly
• You cannot perform mathematical operations on strings
• The def keyword is used to define a function

Python Data Structures

• A list stores values of any data type, including strings and integers
• A dictionary stores values in terms of keys and values
• An array is not a built-in data structure in Python

Python String Operations

• The print function can be used to display strings with newline characters (\n)
• Strings can be concatenated using the + operator
• Strings can be repeated using the * operator

Python Class and Objects

• An object represents an entity in the real world with its identity and behavior
• A class defines an object
• A constructor is used to create an object with assigned values to its members

Python Miscellaneous

• The trunc function returns an integer value
• The help function can be used to get details of a function or module
• The dir function gives a quick list of defined symbols in Python
• Logical connectors are spelled out with letters
• Whitespace indentation affects the meaning of Python code
• Empty string is counted as False in Python boolean operations
• A "raw" string literal is prefixed by an r and passes all characters through without special treatment of backslashes
• REPL stands for Read-Evaluate-Print-Loop
• Unit testing is a method by which individual units of source code are tested to determine if they are fit for use
• A unit is the smallest testable part of an application