我已经定义了一个函数，并且想将它的输出写入一个 txt 文件，我需要在我的代码中进行哪些更改？

Question

print "I can write my function to a txt file:"
my_function = raw_input("File name? ")

print_bills = input(bills(1010, 200, 100, 120))

open(my_function, 'w')
my_function.write('%r' % (print_bills))
my_function.close()

我正在使用 python 并试图将我的函数写入 txt 文件，函数是这样的

def bills(mortgage, elec, oil, ph_int_tv):

    print "Our upcoming mortgage will be approximately %d /month)" % mortgage

    print "Split between my brother and I, that will be %d /month" % (mortgage/2)

    print "With a third roomate, it will be %d /month" % (mortgage/3)

    print "My total bill, per month, with living costs included will be %d /month" % ((mortgage/2)+(elec/2)+(oil/2)+(ph_int_tv/2))

    print "I better start saving money!!\n"

我很新，刚开始阅读 LPTHW 在线书籍...所以我的问题是，我可以在顶部代码中更改什么以使其正常工作...如果有的话？

Answer 1

您可以重新分配标准输出

imporst sys
f = open("test.txt", "w")
sto = sys.stdout   # save stdout so we can revert back to it
sys.stdout = f  # from now on, anything that is printed will go to test.txt

# here, call any method that calls print
# or even 
print "hello"

#finally when no more redirection is desired
f.close()
sys.stdout = sto    # reestablish the regular stdout

您还可以在此StackOverflow question 中找到用于稍有不同目的的有用提示。请注意，其中的一些解决方案可能仅适用于 Unix 系统。

现在，虽然上面显示的技巧是重定向控制台（和/或标准错误，顺便说一句）输出的 权宜之计 方式，而 “我可以在顶部代码中更改什么让它工作” 在暗示这种重定向方法的问题中。您可以考虑重写 bills() 方法，向它传递一个文件，使用 sys.stdout 或您自己选择的文件调用它。比如：

from __future__ import print_function  # might as well get used to Python 3.0 print syntax

def bills(outFile, mortgage, elec, oil, ph_int_tv):
  print("Our upcoming mortgage will be approximately %d /month)" % mortgage, file=outFile)
  print("Split between my brother and I, that will be %d /month" % (mortgage/2), file=outFile)
  print("With a third roomate, it will be %d /month" % (mortgage/3), file=outFile)
  print("My total bill, per month, with living costs included will be %d /month"
          % ((mortgage/2)+(elec/2)+(oil/2)+(ph_int_tv/2)), file=outFile)

  print("I better start saving money!!\n", file=outFile)

Answer 2

def bills(mortgage, elec, oil, ph_int_tv):
    print "Our upcoming mortgage will be approximately %d /month)" % mortgage
    print "Split between my brother and I, that will be %d /month" % (mortgage/2)
    print "With a third roomate, it will be %d /month" % (mortgage/3)
    print "My total bill, per month, with living costs included will be %d /month" % ((mortgage/2)+(elec/2)+(oil/2)+(ph_int_tv/2))
    print "I better start saving money!!\n"

def my_function(my_file,print_bills):
    f=open(my_file, 'w')
    f.write('%r' % (print_bills))
    f.close()

print "I can write my function to a txt file:"
my_file = raw_input("File name? ")

print_bills = bills(1010, 200, 100, 120)


my_function(my_file, print_bills)

Answer 3

基本上，在 Python 中，可以（几乎）像对待任何其他文件对象一样对待标准输出。所以你可以给sys.stdout分配一个文件对象，print语句将被写入文件而不是打印在终端窗口上。

类似下面的方法可能会起作用。

import sys

myfile = open('myfile.txt', 'w')
stdout_bckp = sys.stdout
sys.stdout = myfile
bills(1010, 200, 100, 120)
sys.stdout = stdout_bckp
myfile.close()

如果您在某种 unix 机器上，您还可以重定向从终端启动的程序的输出，如下所示：

$ python myscript.py > myfile.txt