Difference between revisions of "CSC111 Homework 9 Solutions 2011"
(→Problem #2) |
(→Problem #2) |
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python3 elevator.py | python3 elevator.py | ||
Candidates for first boarding of elevator: | Candidates for first boarding of elevator: | ||
| − | + | Lea (78 lbs) | |
| − | + | Leo (180 lbs) | |
| − | + | AI (55 lbs) | |
| − | + | GK (110 lbs) | |
Max weight? 400 | Max weight? 400 | ||
--- BATCH 1 --- | --- BATCH 1 --- | ||
3 people can board the elevator | 3 people can board the elevator | ||
| − | Their combined weight is | + | Their combined weight is 243 |
| − | The selected group includes: | + | The selected group includes: AI, GK, Lea |
| − | The rejected group includes: | + | The rejected group includes: Leo |
--- BATCH 2 --- | --- BATCH 2 --- | ||
1 people can board the elevator | 1 people can board the elevator | ||
| − | Their combined weight is | + | Their combined weight is 180 |
| − | The selected group includes: | + | The selected group includes: Leo |
The rejected group includes: | The rejected group includes: | ||
""" | """ | ||
| + | |||
CANDIDATES = "candidates.txt" | CANDIDATES = "candidates.txt" | ||
def getCandidates( fileName ): | def getCandidates( fileName ): | ||
| + | """gets the contents of the given file and returns all | ||
| + | of its lines, or simply stops the program if the file | ||
| + | cannot be open""" | ||
| + | |||
try: | try: | ||
file = open( fileName, 'r' ) | file = open( fileName, 'r' ) | ||
| Line 204: | Line 209: | ||
print( "Error opening file. Program stopping." ) | print( "Error opening file. Program stopping." ) | ||
exit( 1 ) # stop on the spot! | exit( 1 ) # stop on the spot! | ||
| + | |||
lines = file.readlines() | lines = file.readlines() | ||
file.close() | file.close() | ||
| Line 209: | Line 215: | ||
def getMaxWeight(): | def getMaxWeight(): | ||
| + | """robust input of a positive number. Function keeps on asking | ||
| + | until the user gets it right""" | ||
| + | |||
while True: | while True: | ||
try: | try: | ||
maxWeight = eval( input( "Max weight? ") ) | maxWeight = eval( input( "Max weight? ") ) | ||
| + | |||
if ( maxWeight < 0 ): | if ( maxWeight < 0 ): | ||
print( "Negative weights are invalid. Please try again" ) | print( "Negative weights are invalid. Please try again" ) | ||
else: | else: | ||
return maxWeight | return maxWeight | ||
| + | |||
except (NameError, SyntaxError): | except (NameError, SyntaxError): | ||
print( "Invalid weight. Please try again." ) | print( "Invalid weight. Please try again." ) | ||
| + | |||
def displayEverybody( L ): | def displayEverybody( L ): | ||
| + | """Displays all the people in L, including names and weights""" | ||
L2 = [] | L2 = [] | ||
for weight, name in L: | for weight, name in L: | ||
| Line 225: | Line 238: | ||
print( "Candidates for first boarding of elevator:\n", '\n'.join( L2 ) ) | print( "Candidates for first boarding of elevator:\n", '\n'.join( L2 ) ) | ||
print() | print() | ||
| + | |||
def main(): | def main(): | ||
| + | #--- open file and get lines --- | ||
people = getCandidates( CANDIDATES ) | people = getCandidates( CANDIDATES ) | ||
if len( people )==0: | if len( people )==0: | ||
| Line 286: | Line 301: | ||
main() | main() | ||
| + | |||
</source> | </source> | ||
</onlydft> | </onlydft> | ||
