######## DM2
######## basics 1: loops

######## default loop from 0 to 7
print( "\nfor loop a" )
for i in range( 0, 8 ) :                        ## immutable sequence type, similar (!) to: initiate 0, as long as less than 8, add 1 (i=i+1)
    print i                                     ## print variable i in the indented block
                                                ## instruction block ends with the end of the indent

######## loop from 2 to 7, add 2 at a time
print( "\nfor loop b" )
for i in range( 2, 8, 2 ) :                     ## initiate 2, as long as less than 8, add 2 (i=i+2)
    print( i )
    print( "done!" )                            ## still part of the loop
print( "final i-value: " + str(i) )             ## scope irrelevant, i is available everywhere

######## loop from 1 to 32, whereby the counter is doubled each time NOT WORKING
print( "\nfor loop c" );
a = 1
for i in range( 1, 32, a ) :                    ## as immutable sequence, once initiated no changes possible
    print( i )
    a *= 2
print( "final i-value: " + str(i) )
print( "final a-value: " + str(a) )

######## further details see
######## https://docs.python.org/3/library/functions.html#func-range

######## loop from 1 to 32, whereby the counter is doubled each time
print( "\nwhile loop d" );
a = 1                                           ## set variable a
while ( a<32 ) :                                ## as long as less than 32
    print( a )
    a *= 2                                      ## double (a=a*2)