ValueError：无法将字符串转换为float：['0.016487999999999999']

Question

我正在尝试读取包含字符串数字的文件，但是当我尝试将字符串数字转换为float时，它会给我错误。我知道这可能是因为数字大，但有没有其他方法将字符串数转换为浮点数？我已经查看了现有的解决方案，但我没有找到相关的解决方案。

def load_embeddings(self, FileName = \
                'Resources/EN-wform.w.5.cbow.neg10.400.subsmpl.txt'):

        file = open(FileName,'r')

        for line in file:
            tokens = line.split('\t')

            #since each line's last token content '\n'
            # we need to remove that
            tokens[-1] = str(tokens[-1].split())

            #each line has 400 tokens
            for i in xrange(1, len(tokens)):
                # pass
                print "token ", tokens[i]
                print type(tokens[i])
                print float(tokens[i]) 

输出错误：

token  0.017045999999999999
<type 'str'>
0.017046
token  0.038705999999999997
<type 'str'>
0.038706
token  0.033797000000000001
<type 'str'>
0.033797
token  ['0.016487999999999999']
<type 'str'>
Traceback (most recent call last):
  File "featureExtraction.py", line 51, in <module>
    f.load_embeddings()
  File "featureExtraction.py", line 38, in load_embeddings
    print float(tokens[i])
ValueError: could not convert string to float: ['0.016487999999999999']