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页: 1
原标题:Python For/If Syntax Error

我的守则如下:

for i in tuples:
    if i[0] == "U_shape":
        pieces.append(U_shape(i[1], boardLength, i[2])
    if i[0] == "I_shape":
        pieces.append(I_shape(i[1], i[2])
    if i[0] == "L_shape":
        pieces.append(L_shape(i[1], boardLength, i[2])
    if i[0] == "T_shape":
        pieces.append(T_shape(i[1], boardLength, i[2])
    if i[0] == "X_shape":
        pieces.append(X_shape(i[1], boardLength, i[2])

The Error:

if i[0] == "I_shape":
                    ^
SyntaxError: invalid syntax
问题回答

页: 1

pieceType = {
    "U_shape": U_shape,
    "I_shape": I_shape,
    "L_shape": L_shape,
    "T_shape": T_shape,
    "X_shape": X_shape
}

pieces = [pieceType[a](b, boardLength, c) for a,b,c in tuples]

As others have said, you are missing closing brackets, but that has been said, there is more needed to be done on your code structure:

这是你想要做的事情的真正坏处。 更好的解决办法是使用<条码>第:

mapping = {"U_shape": U_shape, "I_shape": I_shape, ...}
pieces.append(mapping[i[0]](i[1], boardLength, i[2]))

Now, this does rely on all your classes taking the same arguments - and while they don t appear to, this (given the errors already in your code) could be a mistake. If it s not, you could separate out that case, and use the mapping for the other cases.

另一项直接改进是:

for i in tuples:
    if i[0] == "U_shape":
        pieces.append(U_shape(i[1], boardLength, i[2]))
    elif i[0] == "I_shape":
        pieces.append(I_shape(i[1], i[2]))
    elif i[0] == "L_shape":
        pieces.append(L_shape(i[1], boardLength, i[2]))
    elif i[0] == "T_shape":
        pieces.append(T_shape(i[1], boardLength, i[2]))
    elif i[0] == "X_shape":
        pieces.append(X_shape(i[1], boardLength, i[2]))

我猜测,Hugh bothwell将是最快的,但......

>>> import this
The Zen of Python, by Tim Peters
...
In the face of ambiguity, refuse the temptation to guess.
...
>>>

并且使用时间模块衡量。





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