"'utf-8' codec can't decode byte 0xf3" while performing the sentiment lexicon

Question

I am getting an error in the following code while performing the sentiment lexicon. If someone could guide me here, that'd be really helpful.

"'utf-8' codec can't decode byte 0xf3"

from textblob import TextBlob

pos_count = 0
pos_correct = 0

with open("positive.txt","r") as f:
    for line in f.read().split('\n'):
        analysis = TextBlob(line)
        if analysis.sentiment.polarity > 0:
            pos_correct += 1
        pos_count +=1


neg_count = 0
neg_correct = 0

with open("negative.txt","r") as f:
    for line in f.read().split('\n'):
        analysis = TextBlob(line)
        if analysis.sentiment.polarity <= 0:
            neg_correct += 1
        neg_count +=1

print("Positive accuracy = {}% via {} samples".format(pos_correct/pos_count*100.0, pos_count))
print("Negative accuracy = {}% via {} samples".format(neg_correct/neg_count*100.0, neg_count))

Error:

UnicodeDecodeError                        Traceback (most recent call last)
<ipython-input-8-91f2c31897d6> in <module>()
      5 
      6 with open("positive.txt","r") as f:
----> 7     for line in f.read().split('\n'):
      8         analysis = TextBlob(line)
      9         if analysis.sentiment.polarity > 0:

/usr/lib/python3.7/codecs.py in decode(self, input, final)
    320         # decode input (taking the buffer into account)
    321         data = self.buffer + input
--> 322         (result, consumed) = self._buffer_decode(data, self.errors, final)
    323         # keep undecoded input until the next call
    324         self.buffer = data[consumed:]

UnicodeDecodeError: 'utf-8' codec can't decode byte 0xf3 in position 4645: invalid continuation byte