Python: '_io.TextIOWrapper' 类型的对象没有 len()

Question

运行我的代码时，我不断收到错误消息:

TypeError: object of type '_io.TextIOWrapper' has no len() function

我如何让它打开/读取文件并通过循环运行它？

这是我尝试导入的文件的链接:
download link of the DNA sequence

    def mostCommonSubstring():
        dna = open("dna.txt", "r")
        mink = 4
        maxk = 9
        count = 0
        check = 0
        answer = ""
        k = mink
        while k <= maxk:
            for i in range(len(dna)-k+1):
                sub = dna[i:i+k]
                count = 0
                for i in range(len(dna)-k+1):
                    if dna[i:i+k] == sub:
                        count = count + 1
                if count >= check:
                    answer = sub
                    check = count
            k=k+1
        print(answer)
        print(check)

Answer 1

出现问题的原因是您打开文本文件的方式。
您应该添加 dna = dna.read()到您的代码。
所以你的最终代码应该是这样的:

def mostCommonSubstring():
    dna = open("dna.txt", "r")
    dna = dna.read()
    mink = 4
    maxk = 9
    count = 0
    check = 0
    answer = ""
    k = mink
    while k <= maxk:
        for i in range(len(dna)-k+1):
            sub = dna[i:i+k]
            count = 0
            for i in range(len(dna)-k+1):
                if dna[i:i+k] == sub:
                    count = count + 1
            if count >= check:
                answer = sub
                check = count
        k=k+1
    print(answer)
    print(check)