This gist provides a function that makes pep-8-friendly multiline representation of long string.

repr_long_str.py

def repr_long_str(s, maxlen=70, correction=-1, doprint=False):
    assert maxlen > 3
    cur = 0
    out = []
    while cur < len(s):
        end = cur + maxlen - 2 + correction
        while len(repr(s[cur:end])) > maxlen + correction:
            end -= 1
        out.append(repr(s[cur:end]))
        correction = 0
        cur = end
    ret = "(" + "\n".join(out) + ")"
    if doprint:
        print(ret)
        return
    return ret