字符串切片出错吗？

Question

我正在进行一个相当简单的程序，将一个给定的非编码链DNA转换为所有它的对应链(编码、mRNA、tRNA和氨基酸链)。

但是，当我试图分割字符串时，我会得到一个IndexError：

mRNA_parts = mRNA.split(' ')
print mRNA_parts,  # using for debugging purposes

for base in mRNA_parts:
    print base # again, for debugging
    partA = base[0]
    partB = base[1]
    partC = base[2]
    my_acid = (amino_acids[partA][partB][partC]) + ' '
    # 'amino_acids' is a 3D (thrice-nested) dictionary with the corresponding parts of mRNA to convert to the amino acid chain.
    # part of the nested dictionary: amino_acids = {'U': {'U': {'U': 'Phe'}}}. This is only one part (out of 64) of it.
    # Thus, if  the mRNA section was 'UUU', the amino acid would be 'Phe '.
    acid_strand += my_acid

这是我得到的错误：

['GAU', '']
GAU


Traceback (most recent call last):
  File "D:\my_stuff\Google Drive\documents\SCHOOL\Programming\Python\DNA to RNA Converter.py", line 83, in <module>
    main()
  File "D:\my_stuff\Google Drive\documents\SCHOOL\Programming\Python\DNA to RNA Converter.py", line 3, in main
    convert(non_coding)
  File "D:\my_stuff\Google Drive\documents\SCHOOL\Programming\Python\DNA to RNA Converter.py", line 58, in convert
    partA = base[0]
IndexError: string index out of range

它怎么不能做base[0]的基地是'GAU'？

根据它打印的内容，“GAU”不是字符串吗？它周围没有任何报价。

提前感谢！

Answer 1

它显示的不是GAU的错误，而是作为列表第二个元素的空字符串''的错误。在循环开始时添加一个测试来忽略这一点。