排除python中的非ASCII字符

Question

我有一个使用字典解密加密消息的脚本，问题是解密过程会产生大量垃圾（也称为非 ascii）字符。这是我的代码：

from Crypto.Cipher import AES
import base64
import os

BLOCK_SIZE = 32

PADDING = '{'

# Encrypted text to decrypt
encrypted = "WI4wBGwWWNcxEovAe3p+GrpK1GRRQcwckVXypYlvdHs="

DecodeAES = lambda c, e: c.decrypt(base64.b64decode(e)).rstrip(PADDING)

adib = open('words.txt')
for line in adib.readlines():
    secret = line.rstrip('\n')
    if (secret[-1:] == "\n"):
        print "Error, new line character at the end of the string. This will not match!"
    elif (len(secret) >= 32):
        print "Error, string too long. Must be less than 32 characters."
    else:
        # create a cipher object using the secret
        cipher = AES.new(secret + (BLOCK_SIZE - len(secret) % BLOCK_SIZE) * PADDING)

        # decode the encoded string 
        decoded = DecodeAES(cipher, encrypted)
        print decoded+"\n"

到目前为止，我想到的是将decoded 字符串转换为 Ascii，然后排除非 ascii 字符，但它不起作用。

Answer 1

您可以像这样删除非 ascii 字符： 编辑：首先使用解码更新。

output = 'string with some non-ascii characters��@$���9�HK��F�23 some more char'
output = output.decode('utf-8').encode('ascii', 'ignore')

Answer 2

这个版本可以工作：

#!/usr/bin/env python
# -*- coding: UTF-8 -*-

def evaluate_string_is_ascii(mystring):
    is_full_ascii=True
    for c in mystring:
        try:
            if ord(c)>0 and ord(c)<=127:
                #print c,"strict ascii =KEEP"
                pass
            elif ord(c)>127  and ord(c)<=255:
                #print c,"extended ascii code =TRASH"
                is_full_ascii=False
                break
            else:
               # print c,"no ascii  =TRASH"
                is_full_ascii=False
                break
        except:
            #print c,"no ascii  =TRASH"
            is_full_ascii=False
            break
    return is_full_ascii


my_text_content="""azertwxcv
123456789
456dqsdq13
o@��nS��?t#�
lkjal�
kfldjkjl&é"""

for line in my_text_content.split('\n'):

    #check if line contain only ascii
    if evaluate_string_is_ascii(line)==True:

        #print the line
        print line

Answer 3

if six.PY2:
    if isinstance(input_data, str):
        input_data = input_data.decode('ascii', 'ignore').encode('ascii')
    else:
        input_data = input_data.encode('ascii', 'ignore')
else:
    six.PY3
    input_data = str(input_data)

print(input_data)