Question

我有2个文件："a.txt"和"b.txt"我希望匹配它们之间的行。这些文件包含以下内容：

为了匹配这些行，我正在做以下

    a = open("a.txt","r") 
    b = open("b.txt","r")
    for al in a:
        al = al.split()
        val_a = al[0]
        for bl in b:
            bl = bl.split()
            val_b = bl[0]
            print val_a, val_b

令人惊讶的是，print语句ONLY打印出以下内容：

似乎只有一次访问a上的循环。我尝试调试的内容如下：

for al in a:
    al = al.split()
    val_a = al[0]
    print val_a
    for bl in b:
        bl = bl.split()
        val_b = bl[0]

此处的print语句打印a

中的所有值

有人可以帮我解释一下吗？

Answer 1

每次尝试循环时，都需要将文件指针重置为b.txt文件的开头，否则你已经到了最后。

最简单的方法是使用file.seek(0)，如下所示：

a = open("a.txt","r") 
b = open("b.txt","r")
for al in a:
    al = al.split()
    val_a = al[0]

    b.seek(0)

    for bl in b:
        bl = bl.split()
        val_b = bl[0]
        print val_a, val_b

Answer 2

您可以使用b将readlines()提取到一个行列表，然后您可以反复迭代它：

a = open("a.txt","r") 
b = open("b.txt","r").readlines()
for al in a:
    al = al.split()
    val_a = al[0]
    for bl in b:
        bl = bl.split()
        val_b = bl[0]
        print val_a, val_b

Answer 3

试试这个：

import mechanicalsoup

def fetchfile(query):

    url = "http://www.italgiure.giustizia.it/sncass/"

    browser = mechanicalsoup.Browser()
    page = browser.get(url)
    search_form = page.soup.find("form", {"id": "z-form"})
    search_form.find("input", {"id":"searchterm"})["value"] = query
    response = browser.submit(search_form, page.url)

    print(response) # the response is 200, so it should be a good sign

    # actual parsing will come later...
    print("1235" in response.text) # quick-check to see if there is what I'm looking for, but I get False

    # in fact this...
    print(page.text == response.text) # ...gives me True

fetchfile("1235/2012")

说明：

a = open("a.txt","r")
b = open("b.txt","r")
for i,j in zip(a,b):
    print (i.split()[0])
    print (j.split()[0])

Answer 4

将b转换为列表，否则第一次迭代将通过b将使用该文件。

 blist= list(b)

然后是内循环

For bl in blist:
 ...

Python - 如何遍历多个文件的行

4 个答案: