with parameter passingthe parameter name in the function does not need to match the name of the actual parameter in main the definition of could just as well have beendef (whatever)print(whateverglobal constants if you define global variables (variables defined outside of any function definition)they are visible inside all of your functions they have global scope it is good programming practice to avoid defining global variables and instead to put your variables inside functions and explicitly pass them as parameters where needed one common exception is constantsa constant is name that you give fixed data value toby assigning value to the name only in single assignment statement you can then use the name of the fixed data value in expressions later simple example program is constant py'''illustrate global constant being used inside functions ''pi global constant -only place the value of pi is set def circlearea(radius)return pi*radius*radius use value of global constant pi def circlecircumference(radius)return *pi*radius use value of global constant pi def main()print('circle area with radius :'circlearea( )print('circumference with radius :'circlecircumference( )main(this example uses numbers with decimal pointsdiscussed more in decimalsfloatsand floating point arithmetic (page by conventionnames for constants are all capital letters issues with global variables do not come up if they are only used as constants function names defined at the top-level also have global scope this is what allows you to use one function you defined inside another function you definelike calling circlearea from inside main dictionaries definition and use of dictionaries in common usagea dictionary is collection of words matched with their definitions given wordyou can look up its definition python has built in dictionary type called dict which you can use to create dictionaries with arbitrary definitions for character strings it can be used for the common usageas in simple english-spanish dictionary look at the example program spanish py and run it """ tiny english to spanish dictionary is createdusing the python dictionary type dict then the dictionary is usedbriefly "" beginning with python