擅长:python、mysql、java
<pre><code>while True:
try:
mynum = int(input('please enter a positive integer: '))
if mynum >= 0:
# exit loop for positive integer
break;
# loop again for negative integer
print('must be positive integer')
except ValueError as v:
print("Must enter an integer")
myfile = input('Please enter a file name: ')
while True:
try:
with open(myfile, "r") as f:
chars = f.read(mynum)
while chars != "":
chars = f.read(mynum)
print(chars)
break
except IOError as e:
myfile = input('Please enter a different file name: ')
</code></pre>