进一步改进

Question

输入： -

   CRlist
  [['CR', 'FA', 'CL', 'TITLE'], ['409452', 'WLAN', '656885', 'Age out RSSI values from buffer in Beacon miss scenario'], ['379104', 'BT', '656928', 'CR379104: BT doesn\xe2\x80\x99t work that Riva neither sends HCI Evt for HID ACL data nor response to HCI_INQUIRY after entering into pseudo sniff subrating mode.']]

我有以下pythong代码生成HTML代码，但它生成的输出是不期望的，我pring数组值之前似乎有正确的数据在这里，但在使用.format的东西是得到messedup..can任何人点这有什么不对？

for i in range(len(CRlist)):
    if i==0:
        continue
    for j in range(len(CRlist[0])):
        print "i"
        print i
        print "j"
        print j
        print "CRlist[i][j]"
        print CRlist[i][j]//right data here
        CRstring += """
        <tr>
        <td><a href="{CR}">{CR}</a></td>
        <td>{FA}</td>
        <td>{CL}</td>
        <td>{Title}</td>
        </tr>""".format(
            CR=CRlist[i][j],
            FA=CRlist[i][j],
            CL=CRlist[i][j],
            Title=CRlist[i][j],
            )
CRstring += "\n</table>\n"

我对输出的期望却被错误地创建了

   <tr>
   <td><a href="409452">409452</a></td>
   <td>WLAN</td>
   <td>656885</td>
   <td>Age out RSSI values from buffer in Beacon miss scenario</td>
   </tr>
    ..............

实际输出，因为行单元格数据是多余的

                   <tr>
                   <td><a href="409452">409452</a></td>
                   <td>409452</td>
                   <td>409452</td>
                   <td>409452</td>
                   </tr>
                   <tr>
                   <td><a href="WLAN">WLAN</a></td>
                   <td>WLAN</td>
                   <td>WLAN</td>
                   <td>WLAN</td>
                   </tr>
                   <tr>
                   <td><a href="656885">656885</a></td>
                   <td>656885</td>
                   <td>656885</td>
                   <td>656885</td>
                   </tr>
                   <tr>
                   <td><a href="Age out RSSI values from buffer in Beacon miss scenario">Age out RSSI values from buffer in Beacon miss scenario</a></td>
                   <td>Age out RSSI values from buffer in Beacon miss scenario</td>
                   <td>Age out RSSI values from buffer in Beacon miss scenario</td>
                   <td>Age out RSSI values from buffer in Beacon miss scenario</td>
                   </tr>
                   <tr>
                   <td><a href="379104">379104</a></td>
                   <td>379104</td>
                   <td>379104</td>
                   <td>379104</td>
                   </tr>
                   <tr>
                   <td><a href="BT">BT</a></td>
                   <td>BT</td>
                   <td>BT</td>
                   <td>BT</td>
                   </tr>
                   <tr>
                   <td><a href="656928">656928</a></td>
                   <td>656928</td>
                   <td>656928</td>
                   <td>656928</td>
                   </tr>
                   <tr>
                   <td><a href="CR379104: BT doesnΓÇÖt work that Riva neither sends HCI Evt for HID ACL data nor response to HCI_INQUIRY after entering into pseudo sniff subrating mode.">CR379104: BT doesnΓÇÖt work that Riva neither sends HCI Evt for HID ACL data nor response to HCI_INQUIRY after entering into pseudo sniff subrating mode.</a></td>
                   <td>CR379104: BT doesnΓÇÖt work that Riva neither sends HCI Evt for HID ACL data nor response to HCI_INQUIRY after entering into pseudo sniff subrating mode.</td>
                   <td>CR379104: BT doesnΓÇÖt work that Riva neither sends HCI Evt for HID ACL data nor response to HCI_INQUIRY after entering into pseudo sniff subrating mode.</td>
                   <td>CR379104: BT doesnΓÇÖt work that Riva neither sends HCI Evt for HID ACL data nor response to HCI_INQUIRY after entering into pseudo sniff subrating mode.</td>
                   </tr>
/table>

====== PLlist ==========

Answer 1

此代码为每个模板变量提供相同的值：

CR=CRlist[i][j],
FA=CRlist[i][j],
CL=CRlist[i][j],
Title=CRlist[i][j],

显然，这不符合你的意图。这是另一种写作方式：

TEMPLATE = """
    <tr>
    <td><a href="{CR}">{CR}</a></td>
    <td>{FA}</td>
    <td>{CL}</td>
    <td>{Title}</td>
    </tr>
"""

for i, item in enumerate(CRlist):
    if i == 0:
        continue

    CRstring += TEMPLATE.format(
        CR=item[0],
        FA=item[1],
        CL=item[2],
        Title=item[3],
    )

CRstring += "\n</table>\n"

您甚至可以通过切片列表删除i和enumerate位：

for item in CRList[1:]:
    CRstring += # ...

由于您正在生成HTML并且正在使用用户输入（我假设，至少）并且没有转义HTML，因此您有一个XSS漏洞。让我们解决这个问题：

# near the top of the file:
import cgi

# later...
# ...
CRstring += TEMPLATE.format(
    CR=cgi.escape(item[0]),
    FA=cgi.escape(item[1]),
    # ...
)

进一步改进

这一切都很好，但正如有人在评论中指出的那样，你可能最好使用真正的模板引擎。我个人喜欢Jinja2。这是你如何做到的：

    {%- for item in cr_list[1:] %}
        <tr>
            <td><a href="{{ item[0] | escape }}">{{ item[0] | escape }}</a></td>
            <td>{{ item[1] | escape }}</td>
            <td>{{ item[2] | escape }}</td>
            <td>{{ item[3] | escape }}</td>
        </tr>
    {%- endfor %}
</table>

此外，您可能希望将数据放入对象中。例如：

class CREntry(object):
    def __init__(self, cr, fa, cl, title):
        self.cr = cr
        self.fa = fa
        self.cl = cl
        self.title = title

然后你可以很简单地转换它：

entries = [CREntry(*entry) for entry in CRlist[1:]]

然后您的代码变得更加清晰，能够引用entry.title而不是item[3]。

您可能还想使用PEP 8中列出的常规Python约定。

如果你已完成，你的代码如下：

import jinja2

env = jinja2.Environment(autoescape=True)  # no more | escape everywhere!

template = env.from_string(r"""
        {%- for entry in entries %}
            <tr>
                <td><a href="{{ entry.cr }}">{{ entry.cr }}</a></td>
                <td>{{ entry.fa }}</td>
                <td>{{ entry.cl }}</td>
                <td>{{ entry.title }}</td>
            </tr>
        {%- endfor %}
    </table>
""")

class CREntry(object):
    # ...

# later...
entries = [CREntry(*entry) for entry in cr_list]
cr_string = template.render(entries=entries)

在其他地方添加更多代码，但在实际生成HTML时更少，而且我会说更易于维护。

代码生成错误的HTML代码

1 个答案:

进一步改进