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{
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"text": [
"\n",
"['e', 'f', 'g', 'f', 'o', 'e', 'u', 'i', 'f', 'f', 'b', 't', 'u', 'x', 'b', 'm', 'm', 'p', 'g', 'u', 'i', 'f', 'd', 'b', 't', 'u', 'm', 'f']\n",
"\n"
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"source": [
"# ---------------------------------------------------------------\n",
"# python best courses https://courses.tanpham.org/\n",
"# ---------------------------------------------------------------\n",
"# Write a Python program to create a Caesar encryption\n",
"\n",
"# Note : In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code or Caesar shift, is one of the simplest and most widely known encryption techniques.\n",
"# It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet.\n",
"# For example, with a left shift of 3, D would be replaced by A, E would become B, and so on.\n",
"# The method is named after Julius Caesar, who used it in his private correspondence.\n",
"\n",
"# plaintext: defend the east wall of the castle\n",
"# ciphertext: efgfoe uif fbtu xbmm pg uif dbtumf\n",
"\n",
"def caesar_encrypt(realText, step):\n",
"\toutText = []\n",
"\tcryptText = []\n",
"\t\n",
"\tuppercase = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']\n",
"\tlowercase = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']\n",
"\n",
"\tfor eachLetter in realText:\n",
"\t\tif eachLetter in uppercase:\n",
"\t\t\tindex = uppercase.index(eachLetter)\n",
"\t\t\tcrypting = (index + step) % 26\n",
"\t\t\tcryptText.append(crypting)\n",
"\t\t\tnewLetter = uppercase[crypting]\n",
"\t\t\toutText.append(newLetter)\n",
"\t\telif eachLetter in lowercase:\n",
"\t\t\tindex = lowercase.index(eachLetter)\n",
"\t\t\tcrypting = (index + step) % 26\n",
"\t\t\tcryptText.append(crypting)\n",
"\t\t\tnewLetter = lowercase[crypting]\n",
"\t\t\toutText.append(newLetter)\n",
"\treturn outText\n",
"\n",
"code = caesar_encrypt('defend the east wall of the castle', 1)\n",
"print()\n",
"print(code)\n",
"print()"
]
}
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