读取一个文件中的行并查找另一个 txt 文件中列出的所有以 4 字母字符串开头的字符串

Question

我有 2 个 txt 文件（a 和 b_）。

file_a.txt 包含一长串 4 字母组合（每行一个组合）：

aaaa
bcsg
aacd
gdee
aadw
hwer
etc.

file_b.txt 包含各种长度的字母组合列表（有些带有空格）：

aaaibjkes
aaleoslk
abaaaalkjel
bcsgiweyoieotpwe
csseiolskj
gaelsi asdas
aaaloiersaaageehikjaaa
hwesdaaadf wiibhuehu
bcspwiopiejowih
gdeaes
aaailoiuwegoiglkjaaake
etc.

我正在寻找允许我执行以下操作的 python 脚本：

逐行阅读file_a.txt
取每个 4 字母组合（例如 aaai）
阅读file_b.txt并找到所有以4个字母组合开头的各种长度的字母组合（例如aaaibjkes，aaailoiersaaaageehikjaaa, aaailoiuwegoiglkjaaaike 等）
将每次搜索的结果打印在一个单独的 txt 文件中，该文件以 4 个字母的组合命名。

文件aaai.txt:

aaaibjkes 
aaailoiersaaageehikjaaa
aaailoiuwegoiglkjaaake
etc.

文件bcsi.txt:

bcspwiopiejowih
bcsiweyoieotpwe
etc.

对不起，我是新手。请有人指出我正确的方向。到目前为止我只有：

#I presume I will have to use regex at some point
import re

file1 = open('file_a.txt', 'r').readlines()
file2 = open('file_b.txt', 'r').readlines()

#Should I look into findall()?

Answer 1

您可以使用 for 循环逐行打开这两个文件和运行这两个文件。

你可以有两个 for 循环，第一个循环读 file_a.txt 因为你只会读一遍。第二个将通读 file_b.txt 并在开头查找字符串。

为此，您必须使用 .find() 来搜索字符串。因为是开头，所以值应该是0.

file_a = open("file_a.txt", "r")
file_b = open("file_b.txt", "r")

for a_line in file_a:
    # This result value will be written into your new file
    result = ""
    # This is what we will search with
    search_val = a_line.strip("\n")
    print "---- Using " + search_val + " from file_a to search. ----"
    for b_line in file_b:
        print "Searching file_b using " + b_line.strip("\n")
        if b_line.strip("\n").find(search_val) == 0:
            result += (b_line)
    print "---- Search ended ----"
    # Set the read pointer to the start of the file again
    file_b.seek(0, 0)

    if result:
        # Write the contents of "results" into a file with the name of "search_val"
        with open(search_val + ".txt", "a") as f:
            f.write(result)

file_a.close()
file_b.close()

测试用例：

我正在使用你问题中的测试用例：

file_a.txt

aaaa
bcsg
aacd
gdee
aadw
hwer

file_b.txt

aaaibjkes
aaleoslk
abaaaalkjel
bcsgiweyoieotpwe
csseiolskj
gaelsi asdas
aaaloiersaaageehikjaaa
hwesdaaadf wiibhuehu
bcspwiopiejowih
gdeaes
aaailoiuwegoiglkjaaake

程序生成一个输出文件 bcsg.txt，因为它应该包含 bcsgiweyoieotpwe。

Answer 2

希望对您有所帮助；

file1 = open('file_a.txt', 'r')
file2 = open('file_b.txt', 'r')

#get every item in your second file into a list 
mylist = file2.readlines()

# read each line in the first file
while file1.readline():
    searchStr = file1.readline()
    # find this line in your second file
    exists = [s for s in mylist if searchStr in s]
    if (exists):
        # if this line exists in your second file then create a file for it
        fileNew = open(searchStr,'w')
        for line in exists:
            fileNew.write(line)

        fileNew.close()

    file1.close()

Answer 3

试试这个：

f1 = open("a.txt","r").readlines()
f2 = open("b.txt","r").readlines()
file1 = [word.replace("\n","") for word in f1]
file2 = [word.replace("\n","") for word in f2]

data = []
data_dict ={}
for short_word in file1:
    data += ([[short_word,w] for w in file2 if w.startswith(short_word)])

for single_data in data:
    if single_data[0] in data_dict:
        data_dict[single_data[0]].append(single_data[1])
    else:
        data_dict[single_data[0]]=[single_data[1]]

for key,val in data_dict.iteritems():
    open(key+".txt","w").writelines("\n".join(val))
    print(key + ".txt created")

读取一个文件中的行并查找另一个 txt 文件中列出的所有以 4 字母字符串开头的字符串

Read lines in one file and find all strings starting with 4-letter strings listed in another txt file

python

regex

combinations

substring

find