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所以我有一个代码,它是一个突变 dna 生成器——更具体地说,它产生 100 条链,任何碱基的点突变频率为 0.066%,来自我在代码中指定的原始链。然而,我遇到的问题是打印语句。我没有得到输出,我不知道为什么。这是我的代码:

import random

class DNA_mutant_generator:
    def __init__ (self, dna):
        self.dna = dna
        self.bases = bases

    def mutate(self, mutation_rate=0.0066): #add a specification of the mutation rate of 0.066%
        result = []
        mutations = []
        for base in self.dna:
            if random.random() < mutation_rate: #random.random() returns the next random floating point number in range [0.0,1.0)
                new_base = bases[bases.index(base) - random.randint(1, 3)] # subtracts the position of a certain base from a random integer within the range of 1 to 3 in the bases list. This creates the newly mutated base.
                result.append(new_base)#append that new base to the result list
                mutations.append((base, new_base))#appends the original base, as well as the new mutated base to a list of tuples
            else:
                result.append(base)# 
        return "".join(result), mutations # returns mutated strands, as well as mutations

       for result_string, mutations in results:
            if mutations: # skip writing out unmutated strings
                print(result_string, mutations)    

bases = "ACTG" #specifies the bases in the DNA strand
orig_dna = "GGCTCTCCAACAGgtaagcactgaagggtagaaggcatcgtctgtctcagacatgtctggcaccatccgctaagacattaccacgtgggtctcgagtatagctaacacccttctgtttggcagCTTACAGGAGCGAACGTTGG"
dna = orig_dna.upper()
dna_mutants = DNA_mutant_generator(dna)
dna_mutants.mutate()

有人知道我还应该添加什么以获得我在函数中指定的输出吗?我确实包含了一个打印语句,所以我不确定为什么代码没有产生任何结果。

编辑2:

那么代码应该看起来像这样吗?

import random

class DNA_mutant_generator:
    def __init__ (self, dna):
        self.dna = dna
        self.bases = bases

    def mutate(self, mutation_rate=0.0066): #add a specification of the mutation rate of 0.066%
        result = []
        mutations = []
        for base in self.dna:
            if random.random() < mutation_rate: #random.random() returns the next random floating point number in range [0.0,1.0)
                new_base = bases[bases.index(base) - random.randint(1, 3)] # subtracts the position of a certain base from a random integer within the range of 1 to 3 in the bases list. This creates the newly mutated base.
                result.append(new_base)#append that new base to the result list
                mutations.append((base, new_base))#appends the original base, as well as the new mutated base to a list of tuples
            else:
                result.append(base)# 
        return_value = "".join(result), mutations # returns mutated strands, as well as mutations 

        for result_string in results:
            if mutations: # skip writing out unmutated strings
                print(result_string, mutations)
        return return_value

results = [dna_mutants.mutate() for _ in range(100)] #prints 100 strands
bases = "ACTG" #specifies the bases in the DNA strand
orig_dna = "GGCTCTCCAACAGgtaagcactgaagggtagaaggcatcgtctgtctcagacatgtctggcaccatccgctaagacattaccacgtgggtctcgagtatagctaacacccttctgtttggcagCTTACAGGAGCGAACGTTGG"
dna = orig_dna.upper()
dna_mutants = DNA_mutant_generator(dna)
dna_mutants.mutate()

但是如果我将结果移到函数之外,以便在函数内不重复 mutate,我会收到以下错误消息:

 results = [dna_mutants.mutate() for _ in range(100)] #prints 100 strands
NameError: global name 'dna_mutants' is not defined
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1 回答 1

1

您在 print 语句之前返回以下行:

return "".join(result), mutations # returns mutated strands, as well as mutations

如果要在此行之后打印信息,请删除将return表达式分配给变量的语句,然后在函数末尾返回该变量。

    return_value = "".join(result), mutations # returns mutated strands, as well as mutations

   for result_string in result:
        if mutations: # skip writing out unmutated strings
            print(result_string, mutations)  
    return return_value

编辑:您的新问题是因为您创建了一个递归函数,它一遍又一遍地调用自己。每次一个函数调用自己时,它都需要更多的堆栈空间,而且你调用它的次数太多了,你的堆栈“溢出”了。

于 2014-06-10T15:29:38.193 回答