类型错误：“float”类型的对象没有len（）

Question

这里有个错误：对于范围内的j（len（rottati））：

类型错误：“float”类型的对象没有len（）

我看过很多其他的帖子，但是我还没有找到解决办法。 我有点困惑。如果你知道这里发生了什么，请发表评论。

代码是：

m = 22
rlati = numpy.zeros(m)
n = 22
rlongi = numpy.zeros(n)

v = numpy.ndarray((2,),float)

for j in range (len(lati)):
LA = lati[j]
    rlati[j] = LA - latiref

    for i in range (len(longi)):
        LO = longi[i]

    rlongi[i] = LO - longiref

    v[0] = rlati[j]
    v[1] = rlongi[i]

    vv = numpy.matrix(v)
    #transpose of vv as vv.T
    vv = vv.T

    #proper rotation
    vn = R*vv

    #define how many decimals
    vn = numpy.around(vn, decimals =2)

    # rotation of the second column (lati) and third line (longi)
        rotlati = float(vn[0])
    rotlongi = float(vn[1])

s = 22
latidef = numpy.zeros(s)
p = 22
longidef = numpy.zeros(p)

for j in range (len(rotlati)):
RLA = rotlati[j]

    latidef[j] = RLA + latiref

for i in range (len(rotlongi)):
        RLO = rotlongi[i]

    longidef[i]= RLO + longiref

    RLADEF = latidef[j]
    RLODEF = longidef[i]

    return RLADEF, RLODEF

Answer 1

我得到了正确的答案，试试这个：

lloyd = {
    "name": "Lloyd",
    "homework": [90.0, 97.0, 75.0, 92.0],
    "quizzes": [88.0, 40.0, 94.0],
    "tests": [75.0, 90.0]
}

alice = {

    "name": "Alice",
    "homework": [100.0, 92.0, 98.0, 100.0],
    "quizzes": [82.0, 83.0, 91.0],
    "tests": [89.0, 97.0]
}
tyler = {

    "name": "Tyler",
    "homework": [0.0, 87.0, 75.0, 22.0],
    "quizzes": [0.0, 75.0, 78.0],
    "tests": [100.0, 100.0]
}

numbers = []

def average(numbers):

    total = float(sum(numbers))
    return total / len(numbers)

Answer 2

错误正是人们所说的。rotlati是一个float。不能接受len()的float。看看你的代码，你可能会认为意味着创建名为rotlati和rotlongi的列表，并在循环的每次迭代中附加到它们。相反，您当前只是在每次迭代时重写相同的两个浮点变量。

Answer 3

len参数可以是序列（字符串、元组或列表）或映射（字典）。 https://docs.python.org/2/library/functions.html#len

在调用len函数之前，应该验证参数是否属于此类型。您可以调用方法isinstance（）来验证它。看看怎么用。 https://docs.python.org/2/library/functions.html#isinstance