try,except语句

try:
    i+1
    print(i)  #block1
except:
    i=2
    i+=1
    print(i)  #block2

while True:
    a=input('Please enter a number: ')
    try:
        a=float(a)                       #只有输入值能被转化为浮点数时运行
        print('Your number is',a)        #
    except:
        print('That\'s not a number')
    print('Over')

my_info={'age':18,'weight':130,'height':'very very tall'}
try:
    print(my_info['IQ'])
except KeyError:
    print('Ooops, that\'s a KeyError!')

my_info={'age':18,'weight':130,'height':'very very tall'}
print(my_info['IQ'])

my_info={'age':18,'weight':130,'height':'very very tall'}
try:
    print(my_info['IQ'])
except KeyError:
    print('Ooops, that\'s a KeyError!')
except ValueError:
    print('Ooops, that\'s a ValueError!')
except FileNotFoundError:
    print('Ooops, that\'s a FileNotFoundError!')
except IndexError:
    print('Ooops, that\'s a IndexError!')

my_info={'age':18,'weight':130,'height':'very very tall'}
try:
    print(my_info['age'])
except KeyError:
    print('Ooops, that\'s a KeyError!')
else:
    print('完美')

my_info={'age':18,'weight':130,'height':'very very tall'}
try:
    print(my_info['Hobby'])
except KeyError:
    print('Ooops, that\'s a KeyError!')
finally:
    print('结束')