解密结尾的密文

python
cipher="Xkrsg iu xoh xloo,xlkh ju d xay"
shifts=[0,4,1,3]
out=""
i=0
for ch in cipher:
    if ch.isalpha():
        s=shifts[i%len(shifts)]
        base='A' if ch.isupper() else 'a'
        out+=chr((ord(ch)-ord(base)-s)%26+ord(base))
        i+=1
    else:
        out+=ch
print(out)

python
import string
cipher="Xkrsg iu xoh xloo,xlkh ju d xay"
seqs={"0413":[0,4,1,3],"413":[4,1,3],"20260413":[2,0,2,6,0,4,1,3],"2026413":[2,0,2,6,4,1,3],"4132026":[4,1,3,2,0,2,6],"1304":[1,3,0,4],"3140":[3,1,4,0]}
def dec(seq, reset=False, count_non=False):
    out=""; i=0
    for ch in cipher:
        if ch.isalpha():
            s=seq[i%len(seq)]
            base=65 if ch.isupper() else 97
            out+=chr((ord(ch)-base-s)%26+base)
            i+=1
        else:
            out+=ch
            if count_non: i+=1
            if reset and ch in " ,.;": i=0
    return out
for name,seq in seqs.items():
    for reset in [False, True]:
        for count in [False, True]:
            print(name, reset, count, dec(seq,reset,count))
    print()

python
def transform(seq, op=1, reset=False, count_non=False):
    out=''; i=0
    for ch in cipher:
        if ch.isalpha():
            s=seq[i%len(seq)]*op
            base=65 if ch.isupper() else 97
            out+=chr((ord(ch)-base+s)%26+base)
            i+=1
        else:
            out+=ch
            if count_non:i+=1
            if reset and ch in " ,.;": i=0
    return out
for name,seq in seqs.items():
    print(name, transform(seq,1,False,False), transform(seq,1,True,False))

python
plain="There is the hill,high is a way"
for seq in ([0,4,1,3],[4,1,3]):
    out='';i=0
    for ch in plain:
        if ch.isalpha():
            base=65 if ch.isupper() else 97
            out+=chr((ord(ch)-base+seq[i%len(seq)])%26+base); i+=1
        else: out+=ch
    print(seq,out)