如何从python中的文本文件中删除所有带有大写字母和数字和特殊字符的行以及所有长度超过10个字符的行

Question

I have a text file with all existing words in the Dutch language and I need only the words with a specific amount of characters, without any digits or special characters or capitals. I tried to do it by hand (which works) but it's about 400 thousand words :) So I wanted to use Python. I'm very new to Python and I can't find a good solution. With my code (which is far from optimal) I get results but not good enough. Some words seem to be split halfway and concatenated, in some lines two words are not put on a separate line (to name a few things that I don't want).

My question: Is there a simple code that can remove words longer than 10 characters, remove all words starting or containing a Cap, remove all words with special characters? Thank you all in advance.

My code:

import re

input_file = open("basiswoorden-gekeurd.txt", "r+")
output_file = open("word_crumble_wordlist.txt", "w")
filetext = input_file.read()
res_caps = re.sub(r"\s*[A-Z]\w*\s*", " ", filetext).strip()
res_dig = re.sub(r"\s*\d\w*\s*", "", res_caps).strip()
res = re.sub(r"[^a-zA-Z0-9\n\.]\w*\s*", "", res_dig).strip()

for line in res:
    if len(line) < 10:
        output_file.write(line)

Original part of word-list: Original: see the numbers and special characters

Resulting part: Result: looks ok but the word "aaaaagje" seems a combination of other words :) HOW?

Also: Original, with "aanbevolencomité AND aanbevolen" as two separate words on two separate lines And: See "aanbevolencomitaanbevolen"

Answer 1

In this case it might be easier to find matching words, rather than delete unwanted, consider following example let file.txt content be

Capital
okay
thisistoolong
okaytoo
d.o.t.s

then

import re
with open("file.txt","r") as f:
    text = f.read()
for i in re.findall(r'^[a-z]{1,10}$',text,re.MULTILINE):
    print(i)

gives output

okay
okaytoo

Explanation: I use MULTLINE line mode so ^ and $ mean start of line and end of line, then I am finding lines which contain from 1 to 10 lowercase ASCII letters.