如何利用python批量替换字符

[生信程序猿]

有两个文件分别为A.txt, B.txt A.txt的内容,一一对应 A B A B A1 B1 B.txt文件的内容为 A C D A C D A1 C1 D1 请问如何实现在A文件跟B的第一列匹配是用A的第二列替换掉B文件的第一列，生成新的文件。

[一笑程序猴]

最终效果是啥样的，详细描述下
新文件：
B C D
B C D
B1 C1 D1
是这样的吗

[生信程序猿]

对的，是这样的，麻烦了

[萌新自学python中]

就当做是做题了

path = 'C:/Users/Administrator/Desktop/'
file_a = path + 'A.txt'
file_b = path + 'B.txt'
with open(file_a) as a, open(file_b) as b:
    lines_a = a.readlines()
    lines_b = b.readlines()
    content_a =[line_a.split() for line_a in lines_a]
    content_b =[line_b.split() for line_b in lines_b]
    i = 0
    while i in range(len(content_a)):
        idx_a = content_a[i][0]
        idx_b = content_b[i][0]

        if idx_a == idx_b:
            content_b[i][0] = content_a[i][1]
            i += 1
            
    new_file = open(path + 'C.txt', 'w')
    
    for j in range(len(content_b)):
        new_file.write(' '.join(content_b[j])+'\n')
        
    new_file.close()

[生信程序猿]

引用 4 楼 萌新自学python中 的回复:

就当做是做题了

path = 'C:/Users/Administrator/Desktop/'
file_a = path + 'A.txt'
file_b = path + 'B.txt'
with open(file_a) as a, open(file_b) as b:
    lines_a = a.readlines()
    lines_b = b.readlines()
    content_a =[line_a.split() for line_a in lines_a]
    content_b =[line_b.split() for line_b in lines_b]
    i = 0
    while i in range(len(content_a)):
        idx_a = content_a[i][0]
        idx_b = content_b[i][0]

        if idx_a == idx_b:
            content_b[i][0] = content_a[i][1]
            i += 1
            
    new_file = open(path + 'C.txt', 'w')
    
    for j in range(len(content_b)):
        new_file.write(' '.join(content_b[j])+'\n')
        
    new_file.close()

非常感谢

[生信程序猿]

引用 4 楼 萌新自学python中 的回复:

就当做是做题了

path = 'C:/Users/Administrator/Desktop/'
file_a = path + 'A.txt'
file_b = path + 'B.txt'
with open(file_a) as a, open(file_b) as b:
    lines_a = a.readlines()
    lines_b = b.readlines()
    content_a =[line_a.split() for line_a in lines_a]
    content_b =[line_b.split() for line_b in lines_b]
    i = 0
    while i in range(len(content_a)):
        idx_a = content_a[i][0]
        idx_b = content_b[i][0]

        if idx_a == idx_b:
            content_b[i][0] = content_a[i][1]
            i += 1
            
    new_file = open(path + 'C.txt', 'w')
    
    for j in range(len(content_b)):
        new_file.write(' '.join(content_b[j])+'\n')
        
    new_file.close()

非常感谢

[一笑程序猴]

引用 2 楼 林显祖 的回复:

对的，是这样的，麻烦了

def read_write():
    list_a = []
    list_b = []
    with open('a.txt','r') as f_a:
        line_a = f_a.readline().replace('\n','')
        while line_a:
            list_a.append(line_a.split(' '))
            line_a = f_a.readline().replace('\n','')

    with open('b.txt','r') as f_b:
        line_b = f_b.readline().replace('\n','')
        while line_b:
            list_b.append(line_b.split(' '))
            line_b = f_b.readline().replace('\n','')
    for i in range(len(list_a)):
        if list_a[i][0] == list_b[i][0]:
            list_b[i][0] = list_a[i][1]

    with open('c.txt','w') as f_c:
        for l in list_b:
            f_c.writelines(' '.join(l))
            f_c.writelines('\n')
        print('success')

read_write()

[notback]

简单方法，内存够大： 把a读进内存，读个dict 然后遍历b，每行替换。 看你的例子，貌似时行行对应。 a行1对应b行1 这个同时遍历readline不就好了？