我有一個Jinja2字典,我想要一個單一的表達式來修改它 - 或者通過改變它的內容,或者與另一個字典合併。如何修改/合併Jinja2字典?
>>> import jinja2
>>> e = jinja2.Environment()
修改字典:失敗。
>>> e.from_string("{{ x[4]=5 }}").render({'x':{1:2,2:3}})
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "jinja2/environment.py", line 743, in from_string
return cls.from_code(self, self.compile(source), globals, None)
File "jinja2/environment.py", line 469, in compile
self.handle_exception(exc_info, source_hint=source)
File "<unknown>", line 1, in template
jinja2.exceptions.TemplateSyntaxError: expected token
'end of print statement', got '='
兩階段更新:打印多餘的「無」。
>>> e.from_string("{{ x.update({4:5}) }} {{ x }}").render({'x':{1:2,2:3}})
u'None {1: 2, 2: 3, 4: 5}'
>>> e.from_string("{{ dict(x.items()+ {3:4}.items()) }}").render({'x':{1:2,2:3}})
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "jinja2/environment.py", line 868, in render
return self.environment.handle_exception(exc_info, True)
File "<template>", line 1, in top-level template code
TypeError: <lambda>() takes exactly 0 arguments (1 given)
使用dict(x,**y)
:失敗。
>>> e.from_string("{{ dict((3,4), **x) }}").render({'x':{1:2,2:3}})
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "jinja2/environment.py", line 868, in render
return self.environment.handle_exception(exc_info, True)
File "<template>", line 1, in top-level template code
TypeError: call() keywords must be strings
那麼,如何修改的Jinja2字典x
通過改變屬性或與其他詞典合併?
這個問題類似於:How can I merge two Python dictionaries as a single expression?-就Jinja2和Python是類似的。
這應該是我接受的答案^^ – 2016-08-28 15:54:59
'dict.update()'returns'None' – smac89 2017-08-21 22:13:22