AttributeError: 'filter' object has no attribute 'replace' in Python 3
<p>I have some problems with python 3.x. In python 2.x. I could use <code>replace</code> attr in <code>filter</code> obj, but now I cannot use this. Here is a section of my code:</p>

<pre><code>def uniq(seq):
    seen = {}
    return [seen.setdefault(x, x) for x in seq if x not in seen]

def partition(seq, n):
    return [seq[i : i + n] for i in xrange(0, len(seq), n)]

def PlayFairCipher(key, from_ = 'J', to = None):
    if to is None:
        to = 'I' if from_ == 'J' else ''

    def canonicalize(s):
        return list(filter(str.isupper, s.upper()).replace(from_, to))

    m = partition(uniq(canonicalize(key + ascii_uppercase)), 5)

    enc = {}

    for row in m:
        for i, j in product(xrange(5), repeat=2):
            if i != j:
                enc[row[i] + row[j]] = row[(i + 1) % 5] + row[(j + 1) % 5]

    for c in zip(*m):
        for i, j in product(xrange(5), repeat=2):
            if i != j:
                enc[c[i] + c[j]] = c[(i + 1) % 5] + c[(j + 1) % 5]

    for i1, j1, i2, j2 in product(xrange(5), repeat=4):
        if i1 != i2 and j1 != j2:
            enc[m[i1][j1] + m[i2][j2]] = m[i1][j2] + m[i2][j1]

    def sub_enc(txt):
        lst = findall(r"(.)(?:(?!\1)(.))?", canonicalize(txt))
        return ''.join(enc[a + (b if b else 'X')] for a, b in lst)

    return sub_enc
</code></pre>

<p>But when this compiled, I receive this:</p>

<pre><code>AttributeError: 'filter' object has no attribute 'replace'
</code></pre>

<p>How can I fix it?</p>

<p>I think you can use a list comprehension:</p>

<pre><code>[c.replace(from_, to) for c in s.upper() if c.isupper()]
</code></pre>

<p>Is this what you want?  There's a lot of code there so I might be missing something</p>

python python-2.7 python-3.x replace filter