擅长:python、mysql、java
<p>您可以编写自定义函数以在列表中使用:</p>
<pre><code>def get_lowercase_external_id(e):
try:
return e.get('externalEmployeeId', '').lower()
except AttributeError: # 'NoneType' object has no attribute 'lower'
return None
EmployeeIDs = [get_lowercase_external_id(Employee) for Employee in activeEmployees]
</code></pre>
<p>如果要删除所有<code>None</code>id,请改用生成器函数(这比附加到列表的for循环更有效):</p>
<pre><code>def get_lowercase_external_ids(es):
for e in es:
try:
yield e.get('externalEmployeeId', '').lower()
except AttributeError:
continue
EmployeeIDs = list(get_lowercase_external_ids(activeEmployees))
</code></pre>