擅长:python、mysql、java
<p>可能只检查允许的字符更容易:</p>
<pre><code>import string
allowedCharacters = string.digits + string.ascii_uppercase
# allowedCharacters >> 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ
ch = str(input("only give letters and numbers"))
ch = ch.upper()
# check if all characters of the input are in allowedCharacters!
if not all(c in allowedCharacters for c in ch):
print("u didn't put captilized letters and numbers !!")
else:
print("input is fine")
</code></pre>