正则表达式仅从文件中获取以字母开头的单词，并在 python 中删除仅包含数字和标点符号的单词

Question

I have a text file which i am reading in python through nltk functions. I need to get only only words from file starting with letter and removing words with only numbers and punctuation. For ex :-

['Osteama pranay@123  123 !']

so the desired output is

Osteama pranay@123

Please suggest a regular expression for this

Answer 1

import re
' '.join(re.findall(r'\b[a-z][^\s]*\b', 'Osteama pranay@123  123 !', re.I))

the same regexp used with nltk.RegexpTokenizer

import nltk 
tokenizer = RegexpTokenizer(r'[a-zA-Z][^\s]*\b')
nltk.tokenize('Osteama pranay@123  123 !')

Answer 2

To use regular expression you need to >>>import re first

import nltk,re,pprint
from __future__ import division
from nltk import word_tokenize

def openbook(self,book):
    file = open(book)
    raw = file.read()
    tokens = nltk.wordpunct_tokenize(raw)
    text = nltk.Text(tokens)
    words = [w.lower() for w in text]
    vocab = sorted(set(words))
    return vocab
if __name__ == "__main__":
    import sys
    openbook(file(sys.argv[1]))

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