''' Purpose: introductory take on examining a table of values
'''

# define table
# You can think of it like an excel spreadsheet with rows and columns.
table = [ ["A", "B", "C" ],
          [ "D", "E", "F" ],
          [ "G", "H", "I" ],
          [ "J", "K", "L", "M" ]
]

# You can have varying numbers or rows/columns.
# [[1],[2,3],[4,5,6]] is also a valid table.

# A table/dataset (same term) is a list of lists!
# [[],[],[]]
# Each smaller list in your larger list is a row!
# Each element in your smaller list is a cell.

print( "table:", table ) # prints out the list of lists

print()

# determine number of rows in table
nrows = len( table )

# Remember how len( list ) gives you the number of elements?
# The elements in a dataset are the small lists (the rows!)
# So to get the number of rows (number of small lists),
# we can do len( dataset )


print( "the table has", nrows, "rows" )

print()

# print each row of the table along withs number of columns
for row in table : # We are looking at each small list in our table
    ncols = len( row ) # Get the number of elements in each small list (row)
    print( "row", row, "has", ncols, "columns" ) # print it out

# Ex. dataset is [[1,2],[3,4,5]]
# len(dataset) in this case is 2 (2 rows = 2 small lists)
# for row in table:
    # ncols = len( row ) # in my example it will be 2 columns for the first
    # small list [1,2] and 3 columns in the second small list [3,4,5]

# Yes, each element in the smaller list is a cell/column.
# [   [     1 ,    2     , 3   ] , [4    ,5  ]]
    #      cell   cell    cell      cell cell
            #   row                    row
print()

# print each row of the table using row indices
for r in range( 0, nrows ) : # we are looping through the indexes for our rows
    row = table[ r ] # We are getting the row in the dataset using the index
    print( "row", r, ":",  row )
# [[], [], [],[]]
#   0  1   2  3
# nrows = len( table ) = number of rows / number of small lists
# 4 rows indexes 0-3

print()

# individually print each row and column of the table
for r in range( 0, nrows ) : # Loop through indexes for our rows (0 to #rows-1)
    row = table[ r ]     # Get the row in the table using the index
    ncols  = len( row )  # Get the number of cells in the row
                            # (# elements in small list)
    print( "row", r, ":",  row )   # print the row and the row index!
    for c in range( 0, ncols ) :
        # cell = row[ c ] # get the element within the row at index c
        cell = table[r][c] # lines 68 and 69 are the same thing
        print( "    column", c, "of row", r, ":", cell )
        table[r][c] = cell.lower() # convert each cell to lowercase string
    print()

# print the table in people form 
for r in range( 0, nrows ) :
    ncols  = len( table[ r ] )
    for c in range( 0, ncols ) :
        cell = table[ r ][ c ]
        print( cell, end=" " )
    print()