''' Purpose:  demonstrate program user communication
    Author:   Jim Cohoon
    Email id: jpc
'''
# triple quote = header comments
#       ''' everything between these are strings/comments and thus do not get evaluated; only for readers '''
#       can contain many lines
#       usually goes at the top of the program:
#       contains: purpose of the program, author, contact info (your computing id); do this for your hw assignments

# hashtags annotate single lined comments --> everything after is ignored

# comments are ignored!

# comments are helpful to describe what your code is doing but don't over comment;
# Send message to program user : this describes what the print statement does; only for the user! not the program
print( 'Hoos are a single community' ) # this prints whatever is inside () to the console --> generate output
# print() is a built-in FUNCTION; built-in = always available

# the name print() HAS TO BE LOWERCASE; NAMING AND LETTER CASE ARE IMPORTANT
# built-in functions are usually all lowercase
# Print( 'Hoos alive?' ) DOES NOT work; will give you error because python does not recognize it
#       (try uncommenting it - delete the hashtag - then run the code)

# print 'Happy Hump Day' -- DOES NOT work; gives you Syntax error
# () are necessary for ALL functions - this is a syntax rule --> code will not run if a syntax error occurs

# errors will often tell you which line the code went wrong and what is wrong with it; look to error messages and retrace your steps
# always start typing at the very left side; don't indent anything yet

# identifier: sequence of characters that starts with a letter and can be followed by letters and numbers (letters include _ )
#       no limit on the number of characters in the identifier
#       letters should all be lowercase!
#       identifiers are used to annotate something
# style rule for identifier:
#       names should not start with _ unless they have special meanings; in this class, you won't use underscore to start an identifier
# style rules are not strict; the code will still run, but it doesn't look pretty

# statement: instruction to do something

# PyCharm uses color coding to indicate code parts and comments

# whitespace = blank line; used to separate important parts of the program --> makes your code more readable and cleaner
# Python ignores whitespace; doesn't do anything
# doesn't care; program still runs

# code: a singular statement/group of statements
# execute = run --> python evaluates the code you've written from top to bottom

# python interprets code
# makes sure code is legal, have correct syntax --> translate code from top to bottom (this will be important later)

# exit code 0 --> success
# if not 0 --> not successful; something failed
# to run a program: also can right click here, then click Run

print() # print() function does not need an argument (the thing inside parentheses) --> will print a new line in the console (the bottom screen)

# print( rubber ) # will fail without quotes

# can have as many print statements in a program as you want
print( 'rubber' ) # will print what's exactly between the ''
print( "duckies" ) # 'characters' are the same as "characters"; single quotes = double quotes
# '' and "" denote strings/literals: made up of characters (letters, punctuations, symbols, numbers), appearing as exactly inside '' and ""
#       literal is a kind of string
# spaces between things are also whitespaces; will get ignored; helps to make your code more readable
#       print('rubber') == print( 'rubber' ) == print(        'rubber'                       ) --> will only print out 'rubber' in the console
# spaces inside the quotes are part of the string because a space is also a character
#       print( "     duckies" ) --> shows "      duckies" in the console

# you can have comments that go after a line of code --> the rest of that line will be ignored and the code will still run
# (example: lines 61, 62)

# invoking/invocation: when you start a function

# functions have "arguments" = the things inside () and the things you want to be displayed
#       print( 'duckies' ) --> 'duckies' is an argument for the print() function

# print() can have multiple arguments (separated by commas), and the arguments can be of any type
#   can print numbers, decimals, strings
#   can be in any order
#   when elements are separated by commas, each element is separated by a space in the console when you run the program
print( 1, 3.14, 'a, b, c' )

# numbers (integers, decimals) are NOT literals; they are written WITHOUT quotes --> THIS IS IMPORTANT very soon

# when you run a program, it will always run the entire thing!
# debug is a way you can step through each line; it helps you to find out where your code went wrong;
#   you won't have to do this in this class

# yes, PyCharm autosaves whenever you run the program