Question

我正在尝试在两个相同长度的字符串之间找到匹配项，而我正在使用以下代码。

import operator

seq1 = input("Type the first sequence: ")
seq2 = input("Type the second sequence: ")

if len(seq1) != len(seq2):
    print("Sequences must be of the same length")

else:
    for i in range(len(seq1)):
        if (seq1[i] == seq2[i]):
            print ("There are", sum(map(operator.eq, seq1, seq2)), "matches:"+"\n", seq1+"\n", seq2+"\n", "*"*sum(map(operator.eq, seq1, seq2)))

问题是我想把“*”放在匹配的位置，我不知道如何表明这些位置。另一个问题是，当我想打印结果时，每次匹配都会重复一次。我可以给你举个例子：

Type the first sequence: ATCGA
Type the second sequence: AACCA
There are 3 matches:
 ATCGA
 AACCA
 ***
There are 3 matches:
 ATCGA
 AACCA
 ***
There are 3 matches:
 ATCGA
 AACCA
 ***

我真正想要的是以下内容：

Type the first sequence: ATCGA
Type the second sequence: AACCA
There are 3 matches:
 ATCGA
 AACCA
 * * *

Answer 1

您可以使用生成器表达式并将其连接以返回字符串：

str1 = 'ATCGA'
str2 = 'AACCA'

if len(seq1) != len(seq2):
    print("Sequences must be of the same length")

else:

    matches = ''.join('*' if i==j else ' ' for i, j in zip(str1, str2))
    print("There are %d matches" % matches.count("*"))
    print(str1)
    print(str2)
    print(matches)

Answer 2

你可以试试这个：

seq1 = input("Type the first sequence: ")
seq2 = input("Type the second sequence: ")
if len(seq1) != len(seq2):
    print("Sequences must be of the same length")
else:
    asterisk_string = "".join("*" if seq1[i] == seq2[i] else " " for i in range(len(seq1)))
    print("%d matches" % asterisk_string.count("*"))
    print(seq1)
    print(seq2)
    print(asterisk_string)

示例输出：

Type the first sequence: ATCGA
Type the second sequence: AACCA
3 matches
ATCGA
AACCA
* * *

Answer 3

实际上你在这里混合了一些概念。你正在创建一个循环并在循环内部创建map。你只需要一个。

假设您要查找匹配元素的位置：

[i for i in map(operator.eq, seq1, seq2)]

和

matches = [None] * len(seq1)
for i in range(len(seq1)):
    if (seq1[i] == seq2[i]):
        matches[i] = True
    else:
        matches[i] = False

完全等同。

所以要生成一个你想要的结果，你可以改变第二个结果：

seq1 = 'ATCGA'
seq2 = 'AACCA'

matches = [None] * len(seq1)
for i in range(len(seq1)):
    if (seq1[i] == seq2[i]):
        matches[i] = '*'
    else:
        matches[i] = ' '

或替代地图：

matches = ['*' if i else ' ' for i in map(operator.eq, seq1, seq2)]

然后将它们转换为输出：

print(seq1)
print(seq2)
print(''.join(matches))

在两个字符串中查找匹配并标记这些匹配。蟒蛇

3 个答案: