为什么inspect.getsource不返回整个类源代码？

Question

我的 forms.py 中有这段代码：

from django import forms
from formfieldset.forms import FieldsetMixin


class ContactForm(forms.Form, FieldsetMixin):
    full_name = forms.CharField(max_length=120)
    email = forms.EmailField()
    website = forms.URLField()
    message = forms.CharField(max_length=500, widget=forms.Textarea)
    send_notification = forms.BooleanField(required=False)

    fieldsets = ((u'Personal Information',
                {'fields': ('full_name', 'email', 'website'),
                'description': u'Your personal information will not ' \
                                u'be shared with 3rd parties.'}),
                (None,
                {'fields': ('message',),
                'description': u'All HTML will be stripped out.'}),
                (u'Preferences',
                {'fields': ('send_notification',)}))

当我尝试使用 inspect 以编程方式提取代码时，它遗漏了 fieldsets：

In [1]: import inspect

In [2]: import forms

In [3]: print inspect.getsource(forms)
from django import forms
from formfieldset.forms import FieldsetMixin


class ContactForm(forms.Form, FieldsetMixin):
    full_name = forms.CharField(max_length=120)
    email = forms.EmailField()
    website = forms.URLField()
    message = forms.CharField(max_length=500, widget=forms.Textarea)
    send_notification = forms.BooleanField(required=False)

    fieldsets = ((u'Personal Information',
                {'fields': ('full_name', 'email', 'website'),
                'description': u'Your personal information will not ' \
                                u'be shared with 3rd parties.'}),
                (None,
                {'fields': ('message',),
                'description': u'All HTML will be stripped out.'}),
                (u'Preferences',
                {'fields': ('send_notification',)}))

In [4]: print inspect.getsource(forms.ContactForm)
class ContactForm(forms.Form, FieldsetMixin):
    full_name = forms.CharField(max_length=120)
    email = forms.EmailField()
    website = forms.URLField()
    message = forms.CharField(max_length=500, widget=forms.Textarea)
    send_notification = forms.BooleanField(required=False)


In [5]:      

这不会似乎是空行的问题。 我已经测试了中间没有空行，并且在其他属性之间放置了额外的空行。 结果不会改变。

任何想法为什么检查只返回fieldsets之前的部分而不是类的整个源代码？

Answer 1

编辑：根据评论进行修改：

在inspect.getsource(forms.ContactForm)内部，方法BlockFinder.tokeneater()用于确定在哪里ContactForm 块停止。 除此之外，它还会检查 tokenize.DEDENT，它会在存储在 github 的版本中的字段集之前找到它。 该行仅包含换行符，因此 inspect 认为当前块已结束。

如果你插入 4 个空格，它又对我有用了。 我无法争论这背后的基本原理，也许是性能。

class ContactForm(forms.Form):
    full_name = forms.CharField(max_length=120)
    email = forms.EmailField()
    website = forms.URLField()
    message = forms.CharField(max_length=500, widget=forms.Textarea)
    send_notification = forms.BooleanField(required=False)
    # <-- insert 4 spaces here
    fieldsets = ((u'Personal Information',
                {'fields': ('full_name', 'email', 'website'),
                'description': u'Your personal information will not ' \
                                u'be shared with 3rd parties.'}),
                (None,
                {'fields': ('message',),
                'description': u'All HTML will be stripped out.'}),
                (u'Preferences',
                {'fields': ('send_notification',)}))

inspect.getsource(forms) 工作方式不同的原因是，在这种情况下 inspect 不必确定类定义的开始和结束。 它只是输出整个文件。

Answer 2

对我有用。 我的代码中没有“from formfieldset.forms import FieldsetMixin”。 也许这引起了一个问题..