def example_chaining_stuff():
""" Example use of the chaingin hash table.
This example uses a chaining hash table to store
the flags for some number plates, ie, a small
database of flags for plates.
"""
plate1 = NumberPlate('BAA754')
plate2 = NumberPlate('MOO123')
plate3 = NumberPlate('WOF833')
plate4 = NumberPlate('EEK001')
table = ChainingHashTable(5)
table[plate1] = 'Sheep'
table[plate2] = 'Cow'
table[plate3] = 'Dog'
table[plate4] = 'Mouse'
table[plate4] = 'Mouse-updated'
print(table)
print('plate1 in table:', plate1 in table)
print('plate2 in table:', plate2 in table)
print('plate3 in table:', plate3 in table)
print('plate4 in table:', plate4 in table)
print()
print('Value for plate1:', table[plate1])
print('Value for plate2:', table[plate2])
print('Value for plate3:', table[plate3])
print('Value for plate4:', table[plate4])
print()
def example_list_table_stuff():
table = ListTable()
plate1 = NumberPlate('ABC123')
table[plate1] = 'Banana 3'
plate2 = NumberPlate('BOB456')
table[plate2] = 'Banana 2'
plate3 = NumberPlate('JOE234')
table[plate3] = 'Orange 1'
table[plate3] = 'Orange 1-update'
print(plate1 in table) # translates to table.__contains__(flag)
print(table[plate3]) # translates to table.__get_item__(plate)
print(table)
def example_linearhash_stuff():
""" This example uses a linear hash table to store
the flags for some number plates, ie, a small
database of flags for plates.
"""
plate = NumberPlate('AAA000')
flag = 'Overdue fines'
plate2 = NumberPlate('AAA001')
flag2 = ''
plate8 = NumberPlate('AAA001')
flag8 = ''
plate3 = NumberPlate('AAA002')
flag3 = 'jonathan'
plate4 = NumberPlate('AAA003')
flag4 = 'jo'
plate5 = NumberPlate('AAA004')
flag5 = 'jo'
plate6 = NumberPlate('AAA004')
flag6 = 'jo'
plate7 = NumberPlate('AAA005')
flag7 = 'jo'
table = LinearHashTable(6)
table[plate] = flag # translates to table.__set_item__(flag)
table[plate2] = flag2
table[plate8] = flag8 + '-updated'
table[plate3] = flag3
table[plate4] = flag4
table[plate5] = flag5 + '-updated'
table[plate6] = flag6 + '-pass'
table[plate7] = flag7 + '-completed'
print(plate in table) # translates to table.__contains__(flag)
print(table[plate]) # translates to table.__get_item__(plate)
print(table)
def test_records_sequence(max_records):
""" Generates a sequence of (number_plate, flag) records
(NumberPlate('AAA000'), 'AAA000_test_1')
(NumberPlate('AAA001'), 'AAA001_test_2')
(NumberPlate('AAA002'), 'AAA002_test_3')
etc...
n_slots is only used if with_unique_hash is True
"""
records = []
count = 0
for char1 in string.ascii_uppercase:
for char2 in string.ascii_uppercase:
for char3 in string.ascii_uppercase:
for digit1 in string.digits:
for digit2 in string.digits:
for digit3 in string.digits:
plate_str = char1 + char2 + char3
plate_str += digit1 + digit2 + digit3
flag = '{}_{}_{}'.format(
plate_str, TEST_FLAG, count)
number_plate = NumberPlate(plate_str)
record = (number_plate, flag)
records.append(record)
count += 1
#print(count)
if count >= max_records:
return records
return records
def table_test_not_contains(self, n_plates, n_slots, records=None, unique_hash=False):
self.setUp() # needed each time as subtests don't run setup
table = self.table_class(n_slots)
for plate, flag in record_sequence(n_plates, n_slots, unique_hash):
table[plate] = flag
self.assertFalse(NumberPlate('ZZZ999') in table)
return True # only happens if passes
def trial_hash_table(plate_str_list, table):
for plate_str in [
'ABC123', 'DUF721', 'EGG001', 'CSC001', 'ACC101', 'BIG404'
]:
x = NumberPlate(plate_str)
table[x] = 'Stolen' + str(x)
assert table[x] == 'Stolen' + str(x)
print(table)
print()
print(table.condensed_str())
def read_timestamped_block(lines, index):
plate_list = []
num_lines = len(lines)
done = False
while index < num_lines and not done:
current_line = lines[index]
if current_line != '\n':
plate, timestamp = current_line.strip().split(';')
record = (NumberPlate(plate), timestamp)
plate_list.append(record)
#print(record)
index += 1
else:
done = True
return plate_list, index
def basic_db_list(plate_strings):
""" Takes a list of strings and makes a list of tuples
containing (number_plate, flag) pairs.
Each number_plate will be a NumberPlate made from the strings.
The flags will all be str(plate)+'_flag'
This function will be helpful for simple testing :)
>>> example = basic_db_list(['ABC123', 'DEF123', 'BAD321'])
>>> print(example)
[('ABC123', 'ABC123_flag'), ('DEF123', 'DEF123_flag'), ('BAD321', 'BAD321_flag')]
"""
result = []
for plate_str in plate_strings:
plate = NumberPlate(plate_str)
record = (plate, str(plate) + '_flag')
result.append(record)
return result
def read_db_block(lines, index):
""" Makes a list of all the (plate,flag) tuples starting from
the line with the given index, up until a blank line
is reached - the blank line indicates the end of the
section of plate date.
Returns the list of number plates along with the index
of the blank line
"""
plate_list = []
num_lines = len(lines)
done = False
while index < num_lines and not done:
current_line = lines[index]
if current_line != '\n':
plate, flag = current_line.strip().split(':')
record = (NumberPlate(plate), flag)
plate_list.append(record)
#print(record)
index += 1
else:
done = True
return plate_list, index