Удаление пунктуации из списка python

Я думаю, что самый простой способ - извлечь только слова, состоящие из букв:

import re

with open("Tyger.txt") as f:
    words = re.findall("\w+", f.read())

Я бы пошел с чем-то вроде этого:

import re
with open("Tyger.txt") as f:
    print " ".join(re.split("[\-\,\!\?\.]", f.read())

Он удалит только то, что действительно необходимо, и не создаст чрезмерную перегрузку из-за переназначения.

Например:

text = """
Tyger! Tyger! burning bright
In the forests of the night,
What immortal hand or eye
Could frame thy fearful symmetry? 
"""
import re
words = re.findall(r'\w+', text)

or

import string
ps = string.punctuation
words = text.translate(string.maketrans(ps, ' ' * len(ps))).split()

Второй гораздо быстрее.

>>> import re

>>> the_tyger
'\n    Tyger! Tyger! burning bright \n    In the forests of the night, \n    What immortal hand or eye \n    Could frame thy fearful symmetry? \n    \n    In what distant deeps or skies \n    Burnt the fire of thine eyes? \n    On what wings dare he aspire? \n    What the hand dare sieze the fire? \n    \n    And what shoulder, & what art. \n    Could twist the sinews of thy heart? \n    And when thy heart began to beat, \n    What dread hand? & what dread feet? \n    \n    What the hammer? what the chain? \n    In what furnace was thy brain? \n    What the anvil? what dread grasp \n    Dare its deadly terrors clasp? \n    \n    When the stars threw down their spears, \n    And watered heaven with their tears, \n    Did he smile his work to see? \n    Did he who made the Lamb make thee? \n    \n    Tyger! Tyger! burning bright \n    In the forests of the night, \n    What immortal hand or eye \n    Dare frame thy fearful symmetry? \n    '

>>> print re.sub(r'["-,!?.]','',the_tyger)

Отпечатки:

Tyger Tyger burning bright 
In the forests of the night 
What immortal hand or eye 
Could frame thy fearful symmetry 

In what distant deeps or skies 
Burnt the fire of thine eyes 
On what wings dare he aspire 
What the hand dare sieze the fire 

And what shoulder  what art 
Could twist the sinews of thy heart 
And when thy heart began to beat 
What dread hand  what dread feet 

What the hammer what the chain 
In what furnace was thy brain 
What the anvil what dread grasp 
Dare its deadly terrors clasp 

When the stars threw down their spears 
And watered heaven with their tears 
Did he smile his work to see 
Did he who made the Lamb make thee 

Tyger Tyger burning bright 
In the forests of the night 
What immortal hand or eye 
Dare frame thy fearful symmetry 

Или с файлом:

>>> with open('tyger.txt', 'r') as WmBlake:
...    print re.sub(r'["-,!?.]','',WmBlake.read())

И если вы хотите создать список строк:

>>> lines=[]
>>> with open('tyger.txt', 'r') as WmBlake:
...    lines.append(re.sub(r'["-,!?.]','',WmBlake.read()))