[已解决]第20讲 动动手1 后边看不太懂

奔跑的赵云

1. 请用已学过的知识编写程序，找出小甲鱼藏在下边这个长字符串中的密码，密码的埋藏点符合以下规律：i=>|3KYD
i=>|3KYD
    a) 每位密码为单个小写字母Powered by bbs.fishc.com
    b) 每位密码的左右两边均有且只有三个大写字母j~:y
3u=9m7_0 Pzy"pCV#RdwA,21^[t
str1 = '''ABSaDKSbRIHcRHGcdDIF'''

countA = 0  # 统计前边的大写字母
countB = 0  # 统计小写字母
countC = 0  # 统计后边的大写字母
length = len(str1)

for i in range(length):
    if str1[i] == '\n':
        continue

    """
    |如果str1[i]是大写字母：
    |-- 如果已经出现小写字母：
    |-- -- 统计后边的大写字母
    |-- 如果未出现小写字母：
    |-- -- 清空后边大写字母的统计
    |-- -- 统计前边的大写字母
    """
    if str1[i].isupper():
        if countB:
            countC += 1
        else:
            countC = 0
            countA += 1

    """
    |如果str1[i]是小写字母：
    |-- 如果小写字母前边不是三个大写字母（不符合条件）：
    |-- -- 清空所有记录，重新统计
    |-- 如果小写字母前边是三个大写字母（符合条件）：
    |-- -- 如果已经存在小写字母：
    |-- -- -- 清空所有记录，重新统计（出现两个小写字母）
    |-- -- 如果该小写字母是唯一的：
    |-- -- -- countB记录出现小写字母，准备开始统计countC
    """
    if str1[i].islower():
        if countA != 3:
            countA = 0
            countB = 0
            countC = 0
        else:
            if countB:
                countA = 0
                countB = 0
                countC = 0
            else:
                countB = 1
                countC = 0
                target = i

    """
    |如果前边和后边都是三个大写字母：
    |-- 如果后边第四个字母也是大写字母（不符合条件）：
    |-- -- 清空记录B和C，重新统计                                        ##这里看不太明白 为什么如果后边有四个大写字母的话 countA为什么不清零 没有意义了啊
    |-- 如果后边仅有三个大写字母（符合所有条件）：
    |-- -- 打印结果，并清空所有记录，进入下一轮统计
    """
    if countA == 3 and countC == 3:
        if i+1 != length and str1[i+1].isupper():
            countB = 0
            countC = 0
        else:
            print(str1[target], end='')                                                                ##这里也是 为什么countA 不清零 清零不是更好吗
            countA = 3
            countB = 0
            countC = 0

最佳答案

月排行榜 / 总排行榜

gonff

2020-11-16 01:14:36

如果在后面第4个大写字母清零countA，那么如果有第5,6,7个大写字母，就会被当成3个大写字母。     
而有下面这几行：
if str1.islower():
        if countA != 3:
            countA = 0
            countB = 0
            countC = 0
这几行保证了，不清零countA也没关系，因为!=3的情况也包含大于3，所以在这里（再次遇到小写时）会重新清零的。

跳转到最佳答案楼层

奔跑的赵云

今天问题巨多 感谢各位大佬

jackz007

str1 = '''ACFlCTLIQlAIVMTqHFkswqbDDHtpgcWaXSSglUYKE
lqNsYCyaQXBzrFUbkAUAWAKrDgDtAlGMBqWQhpEwquZqWZJpslUfMllCwWptqINjrOBTLuPzwvXNbLCx
oFRritKRpJgBOaGPZdkUzvYnvYmAlEsVmKRXqyQUOdCBqLYyboOYeAQNLnkuiDXCiNiksSSRpDMVQQgs
TmYThnppfKSmkpjjceGLaMOvYgsvNkGENKgGtUSzVPlLMeephDKrWGNpAxBqRiCnQIuKwDZurIRsznUp
xhstMWpHdZzqeEnttlAHiWbhbIJpwKBAGsFWthBiwBDKTFzIUamELZJFLbmqOmwBIYBJIofAUyxTLUEm
LcOXzjIHFcfUfEWccbWzhVuIZMdTVsOaNsLTpHjrvFaYTnJUrqaYnUmbobfOXXtkjKjFUEhVNlPWeaIY
uABNuEDKFWiUaqQiBHGsgEmDSKiJKLkkzFWlobXIyUlDzGcwDnEOwwWxgFpebsslmKItazIYctPROSJp
ImDHusQIkoFQSmuqwdcPNERvflfHtkGTrtbQXqZUsazoxmbVTPIuuxKvfALAaGnIuIZwczCcoIRMncBs
timFGHPJPaHMPTLjsBjIwbbzKyghaDTUStzJceaYAneywwpvdiUJifPHtXmAwZPChWsDmwonzeeQCEiB
xWsJLAtrdVEOBxEaYiSabHdUwlXlDOAKzZUwozJoBGvnFttDkXdYdjQSzzhTIPfYpWVFdiFIqSbyPZIi
VoXunBPbAJVMWluPcIfHmjPeHaTyClCvTOucEYEZXbVDiZMsfeuruDGMmQEsHutzvzVmWvCoPRguBiHh
taTeaguPmNuAxzYJLEcdoApfIFBaLUqettjTJNlHZYlJZRRoKXEvFnoUHdPjDuXuTAubGODkHAokpItw
SlEwhjrUSlfMawWlTMciWAzVcgPcqCHIaogokYAWGsvWZzBfJqzxIkCNvHDvBkOMCyeYXzVVuRJLQIOy
BMoVPgFLOagDxyPfWxTtZQNCLOrVVclPzMNYruNUyMOBKxBvinxuGMAAfndhPsROtkOJAAJQSxpmTzXm
CmEwZOhlItvETUneqvdKLghLyREjuJWRFjVVuNMiPuvvmRaEUmjCXDVuMRAvBuHUYGKPXthWISIbueRp
uvxpmqclmrXpAGFrxhJGxQwlrbkHEmcEUooCoPqGzbrCfIWmtUKmzzXvcqbhxKcAwXCNjbJDWDndKiLK
HwaFKyhXJQgHjIaTfIJrkhUpTHJZebRertDigQtDKxGerMRgHWFTrqqZlcBjAUfTZdFlZCAEZnhzgTIy
gJSsWJjFcCVoFonAfKPTOhTxjxTRtzSKLoIOScEwBCDvWFDVGpBOpijqdwvugoYsyuIOZJTcySDrzy
wBxediHOIYgasrUIDsNZcParqTGfTaBZHoSssXGtiCVvLReyoiitzMpsouqUeMHGWwDMgBaQTRkxPwNP
XsvyFVXfjgKuamMTsEsbeKDgAdVndyDleenPBcXWKGPcDsALDajkCEGufvbtyXUZnelqISbQnHphDoTH
RMIxMKclpWSvQHkzRhdAehBVaKYaXRPMpGaeRxvTRVFfewirvIDoGvYTAvKSoMFCLUNVFVKrYMeYtBrS
KgiBOjvliNOHLrmztypGhQjtpEQwzVfpVqsTUPvOCPzgqOuvLXJBQZHLmSwGTxEMgCAbogXombCiBDNX
BvGtXjrGWbWHtNCoRuqIZPhBQXZiNUhbmzOiyByAoMSBvusppiPVibIqmLXwXEVfcEAyNeUxaEZThULu
mkGmoLrpOEktwRluXvOmmfEWxZkxUNIqZKuzbaUmLKBYrXMmdOYLEzljzbSJnqRbSiAFyUNyyieKITkh
mvkKyosXKCaTsXQIKczJmxuqIEKeGGGwZyWTolQynlWngjDzFMlwhJFEmODeycbEfxgSRbIXySfwlhZZ
BUBhKyGBHRzWGRXAzarcmSDORvaOMOqYlcVIMwlHGtrLMhFWioqeKfvsJdTXmfQzavzSzCRrVzLFMaBT
DMOPFJcjzXcPvBkzacRmVKTQAvVobGRBypFHvoUdjvBhwWXVdDjvfJOocyIHbMqZGMaRaaFFnmtvTSkY
nIHbmPAtuEszMDFURBYxcOJXKMvJbfSbhiaacxhxiZBnoHTcFeqXQfjTqpcMKFpvvzkpSxlDxSlhikFZ
XSplcknpxiZfwUwGsrfpBUkevEiwndkKrVpWKufWpLTWXcyyXehOcDfnzgTAkhwOAcaiHqJWzsuAvMyD
pDJgeCdAJMwatRfcpKQGTkwxHracsYOlZeXoGthHIRfDBYzhuGEQRKFRnqSEbWDCJObWSAoSwFzVZEnI
rVBwXibUaTwnSTwRmIwkIgoGPRiOMLOTvnzEBBCfcugYZwGSsHRKCJoRsxxzRkKwnTRcRNfbMGssqmXV
IKYzyWHIsCjdzxiHEtvHaufVgcoqVkqIQertevTUTIVMYlNXCGEUzQowqsFpciURKoUwqCRogxeghOWs
cMnuAathgFvNIVqqXpmdJDJPhXQpZCyNbTYktMyTUtQEBeQBhEZzqHotmYREADhFodlcPmTMutBZyefW
sBmsnUbVnHUGAyaDirMoowBwXnzrmfHJgfpAquFoHTuvQvIJcjqiqVdntXbgwpVywbsKxqUMNxYVxBmQ
OAcxOAVPuJeOgABYEHhevhnUOgCUuTBAhJcUGsasbMInGCbHnHXWDdXijDRkUYFuOytTcMPtWklmTHTR
XFTfcFfSSqFUFbQVCKEjUOLveXtsHrIfkphXyDkRELnaTfuaZUClLqbdpWAREJHJpycYRDjElqlVeNya
kTCjDpvFrdnlXogrDZdQzAYaePDdfvHWdcaQGgrrHKBdMnMYbsikbkffVsITSUhEapmLGQYbHoiKGRcg
GPLeEvmCOAkGIuDBdnYPlzuUmLOfetGXpbTbPjjWCZiOJxlDazSbEPVpnNLDsLiwlgleiCdPezQwnNWT
ECLuRGpfJZlnZtcghLucmvlOZNwXaikbKGmoGZJIcsfNnmaHIcPXiEYDHjLKpVtNsqemAmaiTIzvLqlU
mlcvraikZozZwBoExUkELoiaAbTAkqDhrARHQyAvWvYUjthfWjZqbQNTnkgmySsORxGcxouYcyCSkjmC
fpTGOlFoXWLINurMZdQURRnZCiZqsEKeVVZdFMnaoUepdAdARtUuXTvkGzmpEVNZiYSWJAwkcSKgAWTD
mUNVxVebIiavuOAxWUBkuUkXCYtRoZhVNwCZGlaANNpBvXgSDeLURUdQnQteKAXbGlOLGYYYCzCGjzua
UmrdPYuRrUBvLFfwBGTiABTmpANdPCptqKwWXARMKrtmbggOBDgNkeHzNUCIXUIuOAavRbLTnzNNRgzL
boTJooLJIdVFbbjWNngnzPznJglCLEWqulqzSuAyvqYdivDqxEtYPKTwVheFmDidEOnLqjPHBcjoOVvt
MCDmQfwNxkOPuxiJqLQOPRAGJappmpikgmrvRAlKjFjTlaznQldBJmzSMDvCWghWOgfhfkHFZBNdbmMf
MsaQHrtJQvZuGFCrPVBNSNZBFZRdpmQNZYZXpkGjXRAXhELlxDfGhiXwgAUujQbqUCiKaRIYruNDRDlL
zInUkJBpySRZoqwQlqmoxADBjjtGjFPLTkcexYGwGYlANZQaXNgKkPXUUqlViVzxPxxtMQPqOxTcChCg
dvKNliVwzRfMmSsBFeuePnbmVqvyfdOXnZpUopEqfCMnnXpfZnNYwNKiZFPUWWmNCMibsyQEhiodVjTz
UxsicVsZNMXyvBLrdJxGGeCPEutNCzYBRamXwRlmVdqUTPnUoAWaVDshgTHZhvhVlLZsoqbyqOjJMPac
hHqiCKhgFkDUhUDSwsrEwaBrKhXINTjYmHvsTyFdRHliydbfQtRFZcsSTfcSfqyIgQuXLZnrdAwylBmW
BRbmVwdoNFcnoxMKHaYOhgihIsKitcrgEkfjIOKsDPOadFhMwVSKWeCfxxxfWjgNiGDaiYDtMhCgedOR
nTYoeVrpGsyDIsuKhffqaEqoqfWukaQlcUShYicuZAdoYVGvRchUgcmNwxQGogDvKhyAkIuqHCIXQfXp
CtkSSTXTugolUKfqSzugIOpyHhIlcTjDBTKPqcyaRhmgFdSBkYurnvnukNGVoxpZBFmwIEmehuaUcoeu
btkjJqKcAAqxgrKcoRGuqHVUHqKgEaqRCIXlaTqaUewJBEWnTnTJIDYdLeGUMDfndHPYTAGQbhxreADo
WZtdvbJVnNGRNvlAsqIPlpXSXEZGBdqVyNCCwylcXprVoGqnPXZioKnqbdrYlDhbsTVDJqRQKoPtQXzu
RnrGgCfYfeRRxiihjItxHurPwtYJoObDzlEABeIRxQocvWrJtyWchmZXJdYvTgicUircdiMKYAkNbdKu
gPpzXnTQIZxtIhvfBfjIHRaDXbYExxYBvrejpEaVHlinHlYRrhsbChnAwTKlQtHntqcqiXZwTUEdlsVy
WFdZNRfqzkhWzeKMGmkuKoSkuSZRkddsuBNFVMFLPeUkLwCCDKagNjMZwtHcVcEEKyjAYubHipuqNjaV
JukystpMZrhBgLqRVMpaIPsyAvYIsBDVqKNCMLqLwyhJhuWDdCPBgSzJTLkJvaGPirOFwfuMtkyXeKoZ
rGPRJqXyhdYNOXVSqGvbSPozAbjhpyfgGVuNUYaRQomzrTtzAMJnYnyvDnuBkbVvmYzhlhqmwgCZaGJG
GGRbaFdfnDlUfCfhpDWTkWfpUDuUksJvRFNxVYBKGoxBCdhmYZwyDPzWihcQXgByRbYxWZslVsbuTHTf
vaulICCTRkkiYuYoqFdzuxsqOBkzEJHbNXhSnHYxyeGoEklCeaUVEtjxmXyOEzcpsAhfKCTejxOxwGYh
eLtoPpPINviTCHUsgzSkycIxtvekMaoZkBIyLboyvMxxaqfviBxkSALNjiNYqGTypcZDvHonaVBZCSLp
SjRTsJmDuPwKnYwCdTprFvbXnrhARNToXpryIfEoIwSWIdfSKeOHDYwgyUvwXXpKUKQEiyZxCsTkAjME
hdxShAAUYJTkprXuFITxxJuKMiphRAyAeUFZgknMMLvUaSjiMlGmLARvTMpllxEQyfvEqkcONHVFcaTW
tqcbVrgeTLTGuJsrjZdYrrjtoLKcEfjkIhjzXgEkYhZggujFJuQlVtSqvuejtxAEqjgXrYjmwLkSRmXp
pkTfONxRyAxRYqJccLxuhabwMTWfwLTlzuVGJtVJOXxwKjFIZENpGHwRvTRitDBQBesRYATKhmWmmmbP
EXOzdBHNeghlqpjJFmzXyADNHQNEThWDyMsGsTmyFnywIPvDSIcxHbKQHgmJEcfsPzYvSYIbQjnTAgzF
UfZAbwfgCMRxtmZQQyayJFFhCSVeeUcQzSLWqhENNUpyLZaJsQsFQsPyFIjGtcmoJaFQGKTFtKUBdBBo
xECKHgYSMcBWnzRvPyihfjwyjhTTavfYqOrbrgZDSrwVYFjNsdxLJIigfMgythUoUIVSydOnfhAaesXZ
kfyDztQiBCMHjfEGLFllxfejLJjanZVRENsXhIxSWDgbvHHOAFtHzqdfquGbdQvOFlhDiWpxwEolxbep
fVfpKYGMNIQuOlmtTkNRDFTVMtVkEXYUDZKfEihbxXsSLGDcKSHSMXZxAturZVEQgismVAgMVVatqjBM
rXeHaGdccPJMlqhVAePDyEoIRTLCwJpkNTuOjEKEvXaAGhWmhWPHCBMVPkcPklbGIvzMzOFplRUsvZbE
vScmmoKktOUVOeKBcqVvoSsplqqssDvLiPqucbrxoNkodsbrZnvoDfyNGyUAURseEuJPUWsEiVCNcUNd
sxzoRVpEFuFloqWLumNVJITKXnWnOlGpCaQgTLJYizixXoxAHHbodRtPHBbnSzZRZOmlWKOQqvHWAhDh
cYBGRQsFwyesMILhiwjnvjeMIZnHYHYNrmOahjrVPuRgsxdfgUbKCZAVfcOizDeQLKiFQmQQUlDHnCQe
lMnlLSrtXhmGDqISCgElUrZXbXjGGkdWadBbxzVojGQwyhAbWMhSKFFwoIqJfIDdZjUdfCYFkpDdIuWe
aFIUFhnlsREthBRoaquSzBVVOPABfuAYZpoalZwNfZMPOptcoQYVUdRYlXuYChPAdRJgFgwPyTszSXIe
qHRtMxyNlPGoBfpjxHnNvwIADmJmquLgMQGtpJAyvflZjFwAgIymerCTnVkjvqPKFVRscOqAhqvCqCjw
BBojzXKIdphOVTFKhBpnIWYRfuqvQZgVMaqNBkYKzqGaEnBFKZukSLdPbXNmcZtMeykLwlLbZqaHayOb
IWZvbxEXXnaozCHeyiYMnWqIAwJxhMIPDsgySMKhdBYmdrGdbJOfJralshwvhWlmatTsylewdimJEzph
tuTzSGOkGDPPvltRVJPdHRPBTAsKWncfjjuHdlEVOeZIvVnUFHmyGTFDlMGVyAIdzLocbTXIHYTopIok
UHFAVjEXPlsMoKTriyGnfeTlVzvGhVZzUAWWPdZNdIxKioQylFMJZmSToyRGsDJKJXQxPkINvmoHCVUc
RIjImkWWxTnDLQiXdmHqQrWBuvguUUubGByTRnJfkNWxsSupcfIVgboDWzqYHEfAnIKCfdYUOslfXPax
YnaJfNLqJgcxRjBmRpOYgNpZOpzMOCVIRiiXdIqqFxPJhQqJadKiCesOsZoWGWbbQSVRZUlbNZdzeUTE
nhdMSCKCPbpWZguZHGkLiWCisjqnaLbJpbRFAHPjGbHOXKZQXoQQZohmVqjTcdWNhXEjPlLKnjpwbMPQ
ybzDvGgkybXtbDmjQuyOrMrcYGRGGfuuPXzieaetSBidnSRPsLaXKGcxDkXmHbqMWZJXsQkwtojlxOeU
KSIFdVvNEnOUmIZDdlnwtJcPBlcpRWNTazpzgItwJotSLWZruzrMlSGASMWDwOqTpeYYHaTHCCurPdwB
AWzUtwblZXNrBYdjUoDacvmRVURqOzUPlnFISsZMFPtthnDHSsFgkYfsMtXFuNPhLTleWVrmelyFaemo
bVIhEAxNwOUDQCOCDIBHsQlFxCbHErKiBsvQNjuIGnIzZiwoVTdUZnucSaKdHrxJeGQfTawFJefGJFFa
GHzELfnGBmkZyorbbDDwhvEVeIYIGLPMEuZduqFjbeWbVfzVIRZNXwPLgcYUsevuhEQXfYcJshYnJaWz
iqvlswEBRKNYEJidlzdWnQJpBtyjHYVpkQGzdYkeREqjhmmnUIbGZVnwwaMKqgXfURSICNxdteUSGhGZ
UEEFhWRoTKGRwFmPpZPOsalsrNOlkTdXqGKoWlWkqJvYYrtLiTfhdItMbbhdumSYgCcQVUARnYFWkCsC
jElZxrQHIlbTHFLOnrutlvyxzaSIdkJgeyMUnUmtXfnaIedbAInAuQssOQqBTLbvFRiqKqUSdUEmcRmN
LvAxlgliymfbjTwDSqNTLcAEIerzpUShNKkuehciEAYeGJOFFcOvurJFUyfZhQqzfaneiBcrPhaphSCB
StQiJvtoPhHcLUbriDUIfifVFnNtJfGlmcbQJSXsZfVjpbqnkMllUmHzLvEuSarSlNlNHsWvYlfhjMEA
epYTjoRGZeAAtURFeDfDxTYmOmONuQQBdcdncFGjhHmKlwqmUWoXuIXIxaaXnNThgPGtIlynrUIPLQTG
xXhattDrfBGbZRveKbgjzxJLdYREQlMeLtcIEUoyJocdAfUbymxuFLVjGkOQniiPParqoyQYfDYAQTkM
WLicLxpEFkBbwlKrTyYilKTtYkpVGxtOjYmcBDOrwFhFiGutmpTyTarUbVUeSevBTdaPDpjRkaEmLJMg
WsMhSGfIcBChcqrRKgKpjvGnFipjswgjetRtniMagakbCXAjpzWTtMlgZGCJwGyglpcLebrKWhgwJfWV
qGifWNEpCtjuejHoyVCdIxzMYGnfoslgTNAJdtVBWDVoGLzHSAVBTnhNIvAOExQNiJOIPPiHkdaRbfaP
ixDDoCDOOeAqvQJFxLWDICfGmufyxmaMshbvcrtjqqVtffZTnbtCOQfzRMGwOQEKaAmSWjnYdNgvdkmd
dQmaKZSdqKNrnvJlcyVMKuNWmuoOeyKecgjXbmSqnpjwJEaDYoehEklEgJyiksGxdEKgfYRXQecRZgfe
qKWGc'''

str = ''
for x in str1:
    str += x . strip()
str = 'a' + str + 'a'
passwd = ''
for k in range(4 , len(str) - 4):
    if str[k - 4] . islower() and str[k - 3 : k] . isupper() and str[k] . islower() and str[k + 1 : k + 4] . isupper() and str[k + 4] . islower():
        passwd += str[k]
print(passwd)

gonff

如果在后面第4个大写字母清零countA，那么如果有第5,6,7个大写字母，就会被当成3个大写字母。     
而有下面这几行：
if str1.islower():
        if countA != 3:
            countA = 0
            countB = 0
            countC = 0
这几行保证了，不清零countA也没关系，因为!=3的情况也包含大于3，所以在这里（再次遇到小写时）会重新清零的。