(NameError:未定义全局名称)将列表传递给函数时出错

时间:2011-11-20 12:47:05

标签: python

很抱歉发布长代码。我已经提取了代码中生成和使用列表lower_lip_under_upper_list_plist的部分。链接使用此列表的函数时出错。 generate_t_u()函数在time()函数内部调用,但time()函数无法识别此列表,因为它未在那里传递。但是如果我在这个函数中传递它,那么我也必须在main中进行更改。我将再次得到同样的错误。

def time(transcriptionFile) :
    """ This function changes the time values in secs from the transcription file and keeps a list of start time for each phoneme. """
    with open("transcriptions.txt", "r") as tFile :
        timeList = []
        t_u = 0.0
        for line in tFile :
            li = line.split()
            if li :
                start_time = (int(li[0]) / 10000000.)
                timeList.append(start_time)
                #print timeList 

    generate_t_u(timeList, lower_lip_under_upper_list_plist)

def generate_t_u(timeList, lower_lip_under_upper_list_plist)
    """ It generates the regular time intervals t(u) values for sampling. """
    i = 0        
    while i < len(timeList) - 1 :
        # if the number is in the range
        # do the calculations and move to the next number
        if t_u > timeList[i] and t_u < timeList[i + 1] :
            #print "\n The t_u value:", t_u, 'is between',
            #print "start:", timeList[i], " and end: ", timeList[i+1]
            poly = poly_coeff(timeList[i], timeList[i + 1], t_u)
            Newton(poly, lower_lip_under_upper_list_plist[i],  lower_lip_under_upper_list_plist[i + 1])
            t_u = t_u + 0.04 # regular time interval

        # if the number is at the lower boundary of the range, no need of calculation as u = 0
        elif t_u == timeList[i] :
            #print "\n The t_u value:", t_u, 'is on the boundary of',
            #print "start:", timeList[i], " and end: ", timeList[i+1]
            #print "u : 0"
            lower_lip_under_upper_list_bezier(0, lower_lip_under_upper_list_plist[i], lower_lip_under_upper_list_plist[i + 1])
            t_u = t_u + 0.04 # regular time interval

        # if the number is at the upper boundary of the range, no need of calculation as u = 1
        elif t_u == timeList[i + 1] :
            #print "\n The t_u value:", t_u, 'is on the boundary of',
            #print "start:", timeList[i], " and end: ", timeList[i+1]
            #print " u : 1"
            lower_lip_under_upper_list_bezier(1, lower_lip_under_upper_list_plist[i], lower_lip_under_upper_list_plist[i + 1])
            t_u = t_u + 0.04 # regular time interval

        # if the number isn't in the range, move to the next range
        else :
            i += 1

def Newton(poly, p0, p3) :
    """ Newton's method for finding the root of a polynomial. Here the root is the 'u' value"""
    poly_diff = poly_differentiate(poly)
    counter = 0
    epsilon = 0.000000000001
    x = 0.5 # initial guess value

    while True:
        x_n = x - (float(poly_substitute(poly, x)) / poly_substitute(poly_diff, x))
        counter += 1
        if abs(x_n - x) < epsilon :
            break
        x = x_n
        #print "\tIteration " , counter , " : ", x_n

     print "u:", (x_n)

    lower_lip_under_upper_list_bezier(x_n, p0, p3)      

def param_lists_separate(pList) :
    """ Separating the parameter values of each feature into individual lists """
    v = [[inner[1][i] for outer in pList for inner in outer]
        for i in range(len(pList[0][0][1]))]

    lower_lip_under_upper_list_plist = v[0]
    lips_part_plist = v[1]
    lips_spread_plist = v[2]
    jaw_open_plist = v[3]
    lips_round_plist = v[4]  

    return lower_lip_under_upper_list_plist

def lower_lip_under_upper_list_bezier(x_n, p0, p3) :
    """ Calculating sampling points using rational bezier curve equation"""
    u = x_n
    p1 = p0
    p2 = p3

    lower_lip_under_upper_list_p_u = math.pow(1 - u, 3) * p0 + 3 * u * math.pow(1 - u, 2) * p1 \
                                 + 3 * (1 - u) * math.pow(u, 2) * p2 + math.pow(u, 3) * p3
    lower_lip_under_upper_list_p_u = lower_lip_under_upper_list_p_u * w
    d = math.pow(1 - u, 3) * w + 3 * u * w * math.pow(1 - u, 2) + 3 * (1 - u) * w * math.pow(u, 2) + math.pow(u, 3) * w
    lower_lip_under_upper_list_p_u = lower_lip_under_upper_list_p_u / d

    print "\n p(u) values for the feature lower lip under upper list \n"
    print "p(u): ", lower_lip_under_upper_list_p_u
    return lower_lip_under_upper_list_p_u

if __name__ == "__main__" :
    time("transcriptions.txt") 

错误是:

  

NameError:未定义全局名称“lower_lip_under_upper_list_plist”。

此错误位于lower_lip_under_upper_list_bezier(0, lower_lip_under_upper_list_plist[i], lower_lip_under_upper_list_plist[i + 1])函数的time()行。

2 个答案:

答案 0 :(得分:2)

考虑time函数中的这一行:

def time(transcriptionFile) :
    ...
    generate_t_u(timeList, lower_lip_under_upper_list_plist)
时间函数中未定义

lower_lip_under_upper_list_plist,因此Python在全局范围内查找它。它也没有在那里定义,所以Python引发了NameError,说没有定义变量lower_lip_under_upper_list_plist


顺便说一下,回溯错误消息包含一个行号,表示导致NameError的行。它将帮助您(和我们)将问题归结为包含行号。

答案 1 :(得分:2)

lower_lip_under_upper_list_plist应该是generate_t_u的返回值吗?尝试将generate_t_u更改为:

def generate_t_u(time_list):
    lower_lip_under_upper_list_plist = []
    # ... the function remains the same
    return lower_lip_upper_list_plist

我不确定调用param_lists_separate的位置,但看起来它中的绑定也应该是全局的。 generate_t_u中存在类似的问题,因为t_u未绑定在那里 - 如果这引用t_u中的time,那么它应该作为参数传入。如果您有许多相关的绑定和方法对数据起作用,那么您应该考虑创建一个将数据和操作联系在一起的类。

请考虑采取以下措施:

class NewtonsMethod(object):
    def __init__(self, file_name):
        # change global names into properties of ``self``
        self.lower_lip_under_upper_list_plist = []
        self.lips_part_plist = []
        self.lips_spread_plist = []
        self.jaw_open_plist = []
        self.lips_round_plist = []
        self.t_u = 0.0
        self.time_list = []
        # initialize from the data file
        with open(file_name) as file_ref:
            for line in file_ref:
                data = line.split()
                if data:
                    start_time = (int(data[0]) / 10000000.0)
                    self.time_list.append(start_time)
    def _lower_lip_under_upper_list_bezier(self, x_n, point):
       (u, p1, p2) = (x_n, self.lower_lip_under_upper_list_plist[point],
                      self.lower_lip_under_upper_list_plist[point + 1])
       # if lower_lip_under_upper_list_p_u is used elsewhere, then it
       # might make sense to change it to a property
       lower_lip_under_upper_list_p_u = ...
       return lower_lip_under_upper_list_p_u
    def _generate_t_u(self):
       (i, t_u) = (0, 0.0)
       while i < len(self.time_list) - 1:
           if t_u > self.time_list[i] and t_u < time_list[i + 1]:
               poly = poly_coeff(self.time_list[i], self.time_list[i + 1], t_u)
               self._apply_newton(poly, i)
           elif t_u == self.time_list[i]:
               self._lower_lip_under_upper_list_bezier(0, i)
               t_u += 0.04
           elif t_u == self.time_list[i + 1]:
               self._lower_lip_under_upper_list_bezier(1, i)
               t_u += 0.04
           else:
               i += 1
    def _apply_newton(self, poly, point):
        poly_diff = poly_differentiate(poly)
        (epsilon, x) = (0.0000000001, 0.5)
        while True:
            x_n = x - (...)
            if abs(x_n - x) < epsilon:
                break
            x = x_n
        self._lower_lip_under_upper_list_bezier(x_n, point)

面向对象编程的最基本原则之一是将算法与它们处理和/或需要的数据捆绑在一起。你可以在这里应用这个想法。您的全局绑定将成为对象的属性,因此它们始终可用作实例方法中self的属性。您可能已经注意到,不再需要传递lower_lip_under_upper_list_plist之类的值。您需要做的就是将索引传递到列表中,因为列表本身是对象的属性。

将算法重构为class应该不再需要全局变量。它还可以最大限度地减少参数的数量,让您专注于以干净和模块化的方式实现算法。