每次调用file.write()时,我都想在字符串中添加换行符。在Python中最简单的方法是什么?


当前回答

对我来说,在print()语句上使用append (a)和open()看起来更容易:

save_url  = ".\test.txt"

your_text = "This will be on line 1"
print(your_text, file=open(save_url, "a+"))

another_text = "This will be on line 2"
print(another_text, file=open(save_url, "a+"))

another_text = "This will be on line 3"
print(another_text, file=open(save_url, "a+"))

其他回答

如果你大量使用它(写了很多行),你可以子类化'file':

class cfile(file):
    #subclass file to have a more convienient use of writeline
    def __init__(self, name, mode = 'r'):
        self = file.__init__(self, name, mode)

    def wl(self, string):
        self.writelines(string + '\n')

现在它提供了一个额外的函数wl来做你想要的:

with cfile('filename.txt', 'w') as fid:
    fid.wl('appends newline charachter')
    fid.wl('is written on a new line')

也许我遗漏了一些东西,比如不同的换行符(\n, \r,…),或者最后一行也以换行符结束,但这对我来说是有效的。

你可以在需要这种行为的特定地方装饰方法write:

#Changed behavior is localized to single place.
with open('test1.txt', 'w') as file:    
    def decorate_with_new_line(method):
        def decorated(text):
            method(f'{text}\n')
        return decorated
    file.write = decorate_with_new_line(file.write)
    
    file.write('This will be on line 1')
    file.write('This will be on line 2')
    file.write('This will be on line 3')

#Standard behavior is not affected. No class was modified.
with open('test2.txt', 'w') as file:
        
    file.write('This will be on line 1')
    file.write('This will be on line 1')
    file.write('This will be on line 1')  

实际上,当你使用多行语法时,就像这样:

f.write("""
line1
line2
line2""")

你不需要添加\n!

通常你会使用\n,但无论出于什么原因,在Visual Studio Code 2019 Individual中它将无法工作。但是你可以用这个:

# Workaround to \n not working
print("lorem ipsum", file=f)  # Python 3.0 onwards only
print >>f, "Text"             # Python 2.0 and under

这是我自己想出来的解决方法为了系统地产生n作为分离器。它使用一个字符串列表,其中每个字符串是文件的一行,但它似乎也可以为您工作。(Python 3 +)。

#Takes a list of strings and prints it to a file.
def writeFile(file, strList):
    line = 0
    lines = []
    while line < len(strList):
        lines.append(cheekyNew(line) + strList[line])
        line += 1
    file = open(file, "w")
    file.writelines(lines)
    file.close()

#Returns "\n" if the int entered isn't zero, otherwise "".
def cheekyNew(line):
    if line != 0:
        return "\n"
    return ""