擅长:python、mysql、java
<p>“工具”可以有条件地定义其类:</p>
<pre><code>fooed = barred = False
try:
import foo
fooed = True
class FooTester(object):
pass # your class here...
except ImportError:
pass
try:
import bar
barred = True
class BarTester(object):
pass # your class here...
except ImportError:
pass
if not fooed or barred:
raise RuntimeError("You are not fooed or barred")
</code></pre>