如何在字符串之前添加unicode字符?(Python)

Question

我希望能够添加一个'u'到一个引用的字符串变量。我需要这样做，因为当我在for循环中，我只能通过变量名访问字符串。

有办法做到这一点吗?

>>> word = 'blahblah'
>>> list = ['blahblah', 'boy', 'cool']
>>> import marisa_trie
>>> trie = marisa_trie.Trie(list)
>>> word in trie
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: Argument 'key' has incorrect type (expected unicode, got str)
>>> 'blahblah' in trie
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: Argument 'key' has incorrect type (expected unicode, got str)
>>> u'blahblah' in trie
True
>>> u"blahblah" in trie
True
>>> u(word) in trie
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'u' is not defined
>>> uword in trie
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'uword' is not defined
>>> u+word in trie
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'u' is not defined
>>> word.u in trie
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'str' object has no attribute 'u'

Answer 1

你可以解码:

lst = ['blahblah', 'boy', 'cool']
for word in lst:
    print(type(word.decode("utf-8")))

或者使用unicode函数:

unicode(word,encoding="utf-8"))

或str.format:

for word in lst:
    print(type(u"{}".format(word)))

Answer 2

我相信unicode(your_string)正是您所需要的。

>>> unicode("Hello world"!)
u"Hello world!"
>>> print (unicode("Hello world"!))
"Hello world!"

Answer 3

是的，format()可以工作，但有时不能。旧版本的Python甚至没有这个功能。我建议:

utext = u"%s" % text

的作用与unicode.format()相同。如果您不喜欢使用unicode()函数。但很明显，你知道。: D

Answer 4

u前缀只能用于文字。要将现有字符串转换为unicode对象，请使用unicode()构造函数。