Python我不能替换字符串值

Question

我正在Visual中用Python3编程。

因此，我的第一个函数生成一个DNA字符串，我的第二个函数应该用两个不同的函数替换该字符串中的1对。我在这里做错什么了。(我得到的错误从错误的语法开始。)

再次感谢你的帮助。

import random as rd


def generateVirus(length):
    a = [rd.choice(["AT", "GC","TA", "CG"])for i in range(length)]
    return ("".join(a))


def mutate(virus):
    virus = [v.replace(virus[int(rd.random()*(len(virus+1))), rd.choice([virus]for v in virus]
    return virus

a = generateVirus(4)
b = virus(a)

Answer 1

import random as rd

dna = ["AT", "GC","TA", "CG"]
def generateVirus(length):
    a = [rd.choice(dna)for i in range(length)]
    return ("".join(a))

def mutate(virus):
    start = int(rd.random()*(len(virus)/2)) *2
    replacement = rd.choice(["AT", "GC","TA", "CG"])
    newvirus = virus[0:start] + replacement + virus[start+2:]
    return newvirus



a = generateVirus(4)
b = mutate(a)
print(a) 
print (b)

现在起作用了

Answer 2

这似乎是平衡的：

def mutate(virus):
    virus = [v.replace(virus[int(rd.random()*(len(virus+1)))]), rd.choice([virus]for v in virus)]
    return virus

但是，您从未定义使用以下方法调用的virus函数：

b = virus(a)