Python 无明显原因的“语法错误：无效语法”
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'Syntax Error: invalid syntax' for no apparent reason
提问by Pearl Philip
I've been trying to get a fix and can't find why the error keeps appearing. Pmin,Pmax,w,fi1 and fi2 have all been assigned finite values
我一直在尝试修复，但找不到错误不断出现的原因。Pmin、Pmax、w、fi1 和 fi2 都已分配有限值
guess=Pmin+(Pmax-Pmin)*((1-w**2)*fi1+(w**2)*fi2)
When i remove this line from the code, the same error appears at the next line of code, again for no reason I can think of
当我从代码中删除这一行时，同样的错误出现在下一行代码中，我再次无缘无故地想到
Edit: Here is the chunk of code I was referring to:
编辑：这是我所指的代码块：
def Psat(self, T):
pop= self.getPborder(T)
boolean=int(pop[0])
P1=pop[1]
P2=pop[2]
if boolean:
Pmin = float(min([P1, P2]))
Pmax = float(max([P1, P2]))
Tr=T/self.typeMolecule.Tc
w=0.5*(1+scipy.tanh((10**5)*(Tr-0.6)))
fi1=0.5*(1-scipy.tanh(8*((Tr**0.4)-1)))
fi2=0.460*scipy.sqrt(1-(Tr-0.566)**2/(0.434**2)+0.494
guess = Pmin+(Pmax-Pmin)*((1-w**2)*fi1+(w**2)*fi2) #error here
solution = scipy.optimize.newton(funcPsat,guess, args=(T,self))
采纳答案by paxdiablo
For problems where it seems to be an error on a line you think is correct, you can often remove/comment the line where the error appears to be and, if the error moves to the next line, there are two possibilities.
对于在您认为正确的行上似乎是错误的问题，您通常可以删除/注释出现错误的行，如果错误移动到下一行，则有两种可能性。
Either bothlines have a problem or the previousline has a problem which is being carried forward. The most likelycase is the second option (even more so if you remove another line and it moves again).
要么两条线都有问题，要么前一条线有问题正在推进。最可能的情况是第二个选项（如果您删除另一条线并再次移动，则更是如此）。
For example, the following Python program twisty_passages.py:
例如，以下 Python 程序twisty_passages.py：
xyzzy = (1 +
plugh = 7
generates the error:
产生错误：
File "twisty_passages.py", line 2
plugh = 7
^
SyntaxError: invalid syntax
despite the problem clearly being on line 1.
尽管问题显然在第 1 行。
In your particular case, that isthe problem. The parentheses in the line beforeyour error line is unmatched, as per the following snippet:
在您的特定情况下，这就是问题所在。根据以下代码段，错误行之前行中的括号不匹配：
# open parentheses: 1 2 3
# v v v
fi2=0.460*scipy.sqrt(1-(Tr-0.566)**2/(0.434**2)+0.494
# ^ ^
# close parentheses: 1 2
Depending on what you're trying to achieve, the solution maybe as simple as just adding another closing parenthesis at the end, to close off the sqrtfunction.
根据您要实现的目标，解决方案可能很简单，只需在末尾添加另一个右括号即可关闭sqrt函数。
I can't say for certainsince I don't recognise the expression off the top of my head. Hardly surprising if (assuming PSAT is the enzyme, and the use of the typeMoleculeidentifier) it's to do with molecular biology - I seem to recall failing Biology consistently in my youth :-)
我不能肯定地说，因为我不认识我头顶上的表情。如果（假设 PSAT 是酶，并且typeMolecule标识符的使用）与分子生物学有关，那就不足为奇了- 我似乎记得我年轻时一直失败的生物学:-)
回答by aaron newland
You're missing a close paren in this line:
您在此行中缺少一个关闭括号：
fi2=0.460*scipy.sqrt(1-(Tr-0.566)**2/(0.434**2)+0.494
There are three ( and only two ).
I hope This will help you.
有三个（而且只有两个）。
我希望这能帮到您。
回答by jbyler
I encountered a similar problem, with a syntax error that I knew should not be a syntax error. In my case it turned out that a Python 2 interpreter was trying to run Python 3 code, or vice versa; I think that my shell had a PYTHONPATH with a mixture of Python 2 and Python 3.
我遇到了类似的问题，语法错误我知道不应该是语法错误。就我而言，结果是 Python 2 解释器试图运行 Python 3 代码，反之亦然；我认为我的 shell 有一个混合了 Python 2 和 Python 3 的 PYTHONPATH。
回答by Ryan w
If you are running the program with python, try running it with python3.
如果您使用 python 运行该程序，请尝试使用 python3 运行它。
