根据映射从给定列表生成列表的Python程序

例如

组织列表:

aa b2 c d 

映射:

aa 1 
b2 2 
d 3 
c 4 

基因列表:

1 2 4 3 

Python 的实现方式是什么？假设 org_list 和映射在文件 org_list.txt 和 mapping.txt 中，而 gen_list 将写入 gen_list.txt

顺便说一句，您认为哪种语言可以非常简单地实现这一点？

请您参考如下方法:

只需使用 list comprehension 遍历列表:

gen_list = [mapping[i] for i in org_list] 

演示:

>>> org_list = ['aa', 'b2', 'c', 'd'] 
>>> mapping = {'aa': 1, 'b2': 2, 'd': 3, 'c': 4} 
>>> [mapping[i] for i in org_list] 
[1, 2, 4, 3] 

如果文件中有此数据，请首先在内存中构建映射:

with open('mapping.txt') as mapfile: 
    mapping = {} 
    for line in mapfile: 
        if line.strip(): 
            key, value = line.split(None, 1) 
            mapping[key] = value 

然后从输入文件构建输出文件:

with open('org_list.txt') as inputfile, open('gen_list.txt', 'w') as outputfile: 
    for line in inputfile: 
        try: 
            outputfile.write(mapping[line.strip()] + '\n') 
        except KeyError: 
            pass  # entry not in the mapping