python 面试题 aac caa相似_Python序列比较-优快云博客

博客内容涉及Python中对两个序列进行比较的代码实现。作者遇到问题，原始代码在比对序列时将不匹配的位置用'|'表示，但在输出时mismatches变量仍为列表形式。经过修改，将mismatches转换为字符串并正确地用'|'连接不匹配项，代码成功运行并展示比对结果。示例序列包括seq_a和seq_b，它们是DNA序列。

我正在尝试比较两个序列：

>>> seq_a = "tgaaactcaagccttaccgcagagacagaagaaacagcaaactgtgactcttcttcctgctgcagatttggatgatttctccaaacaattgcaacaatccatgagcagtgctgactcaactcaggcctaaactcatgcagaccacacaaggcagatgggctatataaacgttttcgcttttccgtttacgatatatagtctactcttgtgcagaatgaattctcgtaactacatagcacaagtagatgtagttaactttaatctcacatagcaatctttaatcagtgtgtaacattagggaggacttgaaagagccaccacattttcaccgaggccacgcggagtacgatcgagtgtacagtgaacaatgctagggagagctgcctatatggaagagccctaatgtgtaaaattaattttagtagtgctatccccatgtgattttaatagcttcttaggagaatgacaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"

>>> seq_b = "agagcctaaaaaggacaaaaagaagaaggctgatgaaactcaagccttaccgcagagacagaagaaacagcaaactgtgactcttcttcctgctgcagatttggatgatttctccaaacaattgcaacaatccatgagcagtgctgactcaactcaggcctaaactcatgcagaccacacaaggcagatgggctatataaacgttttcgcttttccgtttacgatatatagtctactcttgtgcagaatgaattctcgtaactacatagcacaagtagatgtagttaactttaatctcacatagcaatctttaatcagtgtgtaacattagggaggacttgaaagagccaccacattttcaccgaggccacgcggagtacgatcgagtgtacagtgaacaatgctagggagagctgcctatatggaagagccctaatgtgtaaaattaattttagtagtgctatccccatgtgattttaatagcttcttaggagaatgac"

但是我正在使用的代码被卡在sequence_comparison的末尾。这段代码是在网上找到的，我很难找到问题所在。提供的语法错误在最后一段代码的开头突出显示了s：

def sequence_compare(seq_a, seq_b):

len1 = len(seq_a)

len2 = len(seq_b)

mismatches = []

for pos in range (0,min(len1,len2)):

if seq_a[pos] != seq_b[pos]:

mismatches.append('|')

else:

mismatches.append(' ')

print(seq_a)

print(mismatches)

print(seq_b)

sequence_compare(seq_a,seq_b)

有人可以帮我找到这个问题吗？

解决方案

看起来问题在于，mismatches它被显示为列表，而不是字符串。我已经将其转换为字符串：

更新的代码

def sequence_compare(seq_a, seq_b):

len1 = len(seq_a)

len2 = len(seq_b)

mismatches = ""

for pos in range (0,min(len1,len2)):

if seq_a[pos] != seq_b[pos]:

mismatches += '|'

else:

mismatches += ' '

print(seq_a)

print(mismatches)

print(seq_b)

seq_a = "tgaaactcaagccttaccgcagagacagaagaaacagcaaactgtgactcttcttcctgctgcagatttggatgatt"

seq_b = "agagcctaaaaaggacaaaaagaagaaggctgatgaaactcaagccttaccgcagagacagaagaaacagcaaactg"

sequence_compare(seq_a,seq_b)

输出量

tgaaactcaagccttaccgcagagacagaagaaacagcaaactgtgactcttcttcctgctgcagatttggatgatt

| || | |||||||||| ||| |||| || ||||||| ||||| || |||||||||||| ||| | ||| |

agagcctaaaaaggacaaaaagaagaaggctgatgaaactcaagccttaccgcagagacagaagaaacagcaaactg