@virnuls/

# Speed Tracker

## The Speed Tracker task from the OCR Coding Challenges

Files
• main.py
main.py
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```
```from re import match

def validate_registration(plate):
# regular expression to match valid registration
# NB. only accepts new-style registrations, e.g. AB12 CDE
return (match(r"[A-Z][A-Z]\d\d\s[A-Z][A-Z][A-Z]", plate) != None)

# return decimal version of time, e.g. 10:30 = 10.5
def decimalise(time):
# is the time in the right format (i.e. does it have a :)?
valid = time.count(":") == 1
if valid:
times = time.split(":")
try:
return float(times[0]) + float(times[1])/60
except:
print("This is not a valid time.")
valid = False
# return value to show that the time isn't valid
return -1

def speed(start, end):
# if end time is before start time...
if start >= end:
# ... assume that we've gone into the next day
end += 24
# speed = distance/time (and the distance is one mile)
return round(1/(end-start),2)

print("Please use the 24-hour clock for all times.")
# ensure that end has a value
end = -1
# input times and convert to decimal value
start = decimalise(input("Time at first camera (HH:MM): "))
# only ask for the second time if the first one is valid
if start >= 0:
end = decimalise(input("Time at second camera (HH:MM): "))
# only carry on if both times are valid
if start >= 0 and end >= 0:
plate = input("Registration? ")
print("Speed:", speed(start,end), "mph")
print("Valid registration:",validate_registration(plate))```