dir(varName) => Returns list of all methods that can be used
- Define and Call a function
def functionName(arguments):
# statements
functionName(parameters)
- Returning a value
def functionName(arguments):
# statements
return value
varName = functionName(parameters)
- Doesn't gives error for unfinished function
def functionName(arguments):
pass
- Default Arguments
def functionName(varName1=value1, varName2=value2):
# statements
functionName() # Default values will be used
functionName(varName2=value3) # Passing value by argument name
functionName(varName2=value3, varName1=value4) # Order doesn't matter
- Argument as Tuple
def functionName(*varName):
# statements
functionName(value1, value2)
- Argument as Dictionary
def functionName(**varName):
# statements
functionName(key1="value1", key2="value2")
- Docstring => For mentioning function description
def functionName():
'''value'''
# statements
print(functionName.__doc__) # Prints Docstring
print(functionName?) # Prints Docstring
- Recursion => Calling same function inside a function
def functionName(arguments):
# statements
functionName(parameters)
# statements
functionName(parameters)
- Function runs only when original script is running directly and not when it is when imported
def functionName():
# statements
if __name__ == "__main__":
functionName()
- Lambda Function => Small anonymous function without a name, Returns the value, Used as arguments to higher-order function
functionName = lambda arguments: statement
functionName = lambda argument1, argument2: statement
varName = functionName(parameters)
- Decorator => Tool that allows you to modify the behavior of function and methods, Used to add functionality like logging, memoization, access control
def functionName1(fx):
def mfx(*args, **kwargs):
# Statements
fx(*args, **kwargs)
# Statements
return mfx
@functionName1
def functionName(arguments):
# Statements
functionName(parameters)
# OR
functionName1(functionName)(parameters) # @ is not required