In this answer i have written the line2cipher and logMap function, i assume that the genAmpSeed and cipherchr() will be already defined as provided in the question.

password=input("Enter the password: ")
amp,seed=genAmpSeed(password)
line=input("Enter line to be ciphered: ")

def logMap(j,k):
    ans=(j*k)*(1-k)
    return ans

def line2cipher(amp,seed,line):
    acc=''
    for i in line[1:]:
        r=logMap(amp,seed)
        offset=int(96*r)
        acc+= cipherChr(i,offset)
    return amp, offset, acc