擅长:python、mysql、java
<p>你可以这样做:</p>
<pre><code>def get_number(hint):
while True:
try:
value = int(input(hint))
except ValueError:
print('Please input a number')
continue
if value<0:
print('Please input a positive value')
continue
else:
break
return value
Auto_details = {'Car brand': input('Car brand:'),
'Car model': input('Car model:'),
'Model Year': input('Model Year:'),
'Starting odometer reading': get_number('Starting odometer reading:'),
'Ending odometer reading': get_number('Ending odometer reading:'),
'Miles per gallon': get_number('Miles per gallon:'),
}
print(Auto_details)
input ('Thank you. Please press Enter to exit')
</code></pre>