Python UnboundLocalError:局部变量

我的代码如下：

search_request = urllib2.Request(url,data=tmp_file_name,headers={'X-Requested-With':'WoMenShi888XMLHttpRequestWin'})
#print search_request.get_method()
try:
    search_response = urllib2.urlopen(search_request)
except urllib2.HTTPError:
    pass
html_data = search_response.read()
print html_data

但当我运行它时，我得到了：

Traceback (most recent call last):
  File "G:\MyProjects\python\lfi_tmp.py", line 78, in <module>
    print hello_lfi()
  File "G:\MyProjects\python\lfi_tmp.py", line 70, in hello_lfi
    html_data = search_response.read()
UnboundLocalError: local variable 'search_response' referenced before assignment

然后再次运行，我会遇到这样的异常

Traceback (most recent call last):
  File "G:\MyProjects\python\lfi_tmp.py", line 78, in <modul
    print hello_lfi()
  File "G:\MyProjects\python\lfi_tmp.py", line 70, in hello_
    html_data = search_response.read()
NameError: global name 'search_response' is not defined

回溯（最近一次呼叫最后一次）：
文件“G:\MyProjects\python\lfi\u tmp.py”，第78行，在中，如果您得到
HTTPError
您没有
search\u响应
变量。所以这一行：

html_data = search_response.read()

引发错误，因为您正试图访问未声明的
搜索\u响应
。我认为您应该替换
html\u data=search\u response.read（）
行，例如：

search_request = urllib2.Request(url,data=tmp_file_name,headers={'X-Requested-With':'WoMenShi888XMLHttpRequestWin'})
    #print search_request.get_method()
try:
    search_response = urllib2.urlopen(search_request)
    html_data = search_response.read()  #New here
except urllib2.HTTPError:
    html_data = "error" #And here

print html_data

代码将进入下面代码中的
异常
，其中未设置
search\u response
变量

try:
    search_response = urllib2.urlopen(search_request)
except urllib2.HTTPError:
    pass
html_data = search_response.read()
print html_data

不要使用
pass
，而是引发错误或将
search\u response
变量设置为
None

可能是这样的：

try:
    search_response = urllib2.urlopen(search_request)
except urllib2.HTTPError:
    raise SomeError
html_data = search_response.read()
print html_data

或

try:
    search_response = urllib2.urlopen(search_request)
except urllib2.HTTPError:
    raise SomeError
html_data = search_response.read()
print html_data

try:
    search_response = urllib2.urlopen(search_request)
except urllib2.HTTPError:
    search_response = None
if html_data:
    html_data = search_response.read()
    print html_data
else:
    # Do something else