Python-将字符串打印到文本文件

Question

我正在使用Python打开文本文档：

text_file = open("Output.txt", "w")

text_file.write("Purchase Amount: " 'TotalAmount')

text_file.close()

我想将字符串变量的值替换TotalAmount为文本文档。有人可以让我知道怎么做吗？

Answer 1

text_file = open("Output.txt", "w")
text_file.write("Purchase Amount: %s" % TotalAmount)
text_file.close()

如果使用上下文管理器，则将自动为你关闭文件

with open("Output.txt", "w") as text_file:
    text_file.write("Purchase Amount: %s" % TotalAmount)

如果你使用的是Python2.6或更高版本，则最好使用 str.format()

with open("Output.txt", "w") as text_file:
    text_file.write("Purchase Amount: {0}".format(TotalAmount))

对于python2.7及更高版本，你可以使用{}代替{0}

在Python3中，file该print函数有一个可选参数

with open("Output.txt", "w") as text_file:
    print("Purchase Amount: {}".format(TotalAmount), file=text_file)

Python3.6引入了f字符串作为另一种选择

with open("Output.txt", "w") as text_file:
    print(f"Purchase Amount: {TotalAmount}", file=text_file)