Question

我想找出为什么第二个字符串＆＃34; peptide_seq＆＃34;绕过第一个if声明？这三个字符串应该通过if语句并返回以下语句：

将字符串转换为大写。


包含任何不是A C G T或U的字符的字符串应返回：＆＃34;不是明确的核苷酸＆＃34;。

包含ACGU的字符串应返回＆＃34; DNA＆＃34;。

包含ACGT的字符串应返回＆＃34; RNA＆＃34;。

def nuc_ac_check(string):
    input_string = string.upper()

    if ('d') in input_string:
        return "not an unambiguous nucleic acid"
    elif ('A' and 'C' and 'G' and 'U') in input_string:
        return "Rna"
    elif ('A' and 'C' and 'G' and 'T') in input_string:
        return "Dna"

Rna_seq = "GGUACGGCUUGGUAUCCCACUCAGUGGCACCUGUGGCCU"
peptide_seq= "acgsdtushnsdses"
Dna_seq = "ggatacgatc"

print ('the rna seq variable is: ' + nuc_ac_check(Rna_seq))
print ('the peptide seq variable is: ' + nuc_ac_check(peptide_seq))
print ('the Dna seq variable is: ' + nuc_ac_check(Dna_seq))

Answer 1

第一个条件应该按照以下方式修复：

 if ('D') in input_string:
    return "not an unambigious nucleic acid"

注意大写＆＃39; D＆＃39;在这种情况下。

<强>更新完整代码，使用Holloway和rassar评论： 更新1： 完整代码，使用Holloway和rassar，以及Copperfield评论：

def nuc_ac_check(string):
    input_string = string.upper()

    rna_letter = ['A', 'C', 'G', 'U']
    dna_letter = ['A', 'C', 'G', 'T']

    if ('D') in input_string:
        return "not an unambigious nucleic acid"
    elif all(letter in rna_letter for letter in input_string):
        return "Rna"
    elif all(letter in dna_letter for letter in input_string):
        return "Dna"
    return "Nothing of everything above"

Rna_seq = "GGUACGGCUUGGUAUCCCACUCAGUGGCACCUGUGGCCU"
peptide_seq= "acgsdtushnsdses"
Dna_seq = "ggatacgatc"
weird_string = "AGCTEXF"

print ('the rna seq variable is: ' + nuc_ac_check(Rna_seq))
print ('the peptide seq variable is: ' + nuc_ac_check(peptide_seq))
print ('the Dna seq variable is: ' + nuc_ac_check(Dna_seq))
print ('the weird string variable is: ' + nuc_ac_check(weird_string))

Answer 2

你不能说：

elif ('A' and 'C' and 'G' and 'T') in input_string:

你必须说：

elif 'A' in input_string and 'C' in input_string and 'G' in input_string and 'T' in input_string:

或者你可以让它更简洁：

elif all(letter in input_string for letter in ('A', 'C', 'G', 'T')):

所以试试这个：

if all(letter in input_string for letter in ('A', 'C', 'G', 'U')):
    return "Rna"
elif all(letter in input_string for letter in ('A', 'C', 'G', 'T')):
    return "Dna"
else:
    return "not an unambiguous nucleic acid"

Answer 3

.upper（）将转换大写中的所有内容。其他条件如('A' and 'C' and 'G' and 'T')将始终给出一个char，因此您需要更新if子句。你应该尝试这样的事情。

def containsAny(seq, aset):
    """ Check whether sequence seq contains ANY of the items in aset. """
    for c in seq:
        if c in aset: return True
    return False

def nuc_ac_check(string):
    input_string = string.upper() # update it as per your need

    if ('d') in input_string:
        return "not an unambigious nucleic acid"
    elif containsAny(input_string,['A','C','G','U']):
        return "Rna"
    elif containsAny(input_string,['A','C','G','T']):
        return "Dna"

Rna_seq = "GGUACGGCUUGGUAUCCCACUCAGUGGCACCUGUGGCCU" peptide_seq= "acgsdtushnsdses" Dna_seq = "ggatacgatc"

print ('the rna seq variable is: ' + nuc_ac_check(Rna_seq)) print ('the peptide seq variable is: ' + nuc_ac_check(peptide_seq)) print ('the Dna seq variable is: ' + nuc_ac_check(Dna_seq))

Answer 4

我不确定你要做什么，但这可能会起作用：

dna_set = set("ATGC")
rna_set = set("AUGC")
nucleotide_set = set("ATGCU")

def nuc_ac_check(string):
    str_set = set(string.upper())

    if str_set - nucleotide_set != set():
        return "Not an unambiguous nucleic acid"
    if str_set == rna_set:
        return "RNA"
    if str_set == dna_set:
        return "DNA"
    return "Not DNA or RNA"

Answer 5

只是询问字符串中是否包含"d"或"D"不足以排除无效字符串，因为它可能包含"E"，"Z"，{ {1}}，"X"，"1"或任何其他可能的角色，在我看来，最好的解决方案是使用set，这会减少你给它的任何东西不同的元素

例如

"@"

然后你只需要与有效选项的集合进行比较，看看是否有任何匹配

>>> set("111122222222ddddddddRRRRRRRDDDDD")
{'D', '1', 'd', '2', 'R'}
>>>

，输出

RNA = set("ACGU")
DNA = set("ACGT")

def nuc_ac_check(string):
    d_r_na = set(string.upper())

    if d_r_na == DNA:
        return "DNA"
    elif d_r_na == RNA:
        return "RNA"
    else:
        return "not an unambiguous nucleotide"


Rna_seq = "GGUACGGCUUGGUAUCCCACUCAGUGGCACCUGUGGCCU"
peptide_seq= "acgsdtushnsdses"
Dna_seq = "ggatacgatc"

print('the rna seq variable is: ' + nuc_ac_check(Rna_seq))
print('the peptide seq variable is: ' + nuc_ac_check(peptide_seq))
print('the Dna seq variable is: ' + nuc_ac_check(Dna_seq))

为什么if语句被绕过？

5 个答案: