With the following MWE:
使用以下MWE：
with open('a','w') as f:
f.write('\r')
with open('a','r') as f:
print(ord(f.read()))
I get the following output:
我得到以下输出：
$ python2 test.py
13
$ python3 test.py
10
Can you explain why? 13 is the expected decimal number of \r in ascii and UTF-8 as far as I can tell.
你能解释一下原因吗？ 13是ascii和UTF-8的预期十进制数\ r \ n据我所知。
1 个解决方案
#1
7
Python 3's open defaults to universal newlines mode (newline=None), while Python 2's open only enables universal newlines mode if the mode string include U.
Python 3的open默认为通用换行模式（newline = None），而Python 2的open仅在模式字符串包含U时启用通用换行模式。
In universal newlines mode, a sequence \r (old Mac), \n (UNIX) or \r\n (DOS/Windows) are all recognized as newlines, and automatically converted to \n so line endings have a consistent representation to simplify string manipulation.
在通用换行模式下，序列\ r \ n（旧Mac），\ n（UNIX）或\ r \ n（DOS / Windows）都被识别为换行符，并自动转换为\ n，因此行结尾具有一致的表示形式以简化字符串操作。
If you want universal newlines in Python 2, you can either use the mode string to enable it or use io.open, which is a near exact equivalent of Python 3's built-in open (io.open on Python 3 is just another way to say open).
如果你想在Python 2中使用通用换行符，你可以使用模式字符串来启用它，或者使用io.open，它几乎完全等同于Python 3的内置开放（Python 3上的io.open只是另一种方式说开放）。
If you want to disable universal newlines handling on Python 3, pass open an argument of newline='' (for universal recognition for the purposes of breaking lines when reading/iterating, but no translation of line endings) or newline='\n' (for example) to mean only \n is recognized as a line ending at all, and again, no translation of line endings is performed. Passing newline='' is required to properly handle certain file formats; the csv module performs its own line ending handling, and newline='' ensures no information is lost before it reaches the csv reader.
如果要在Python 3上禁用通用换行符处理，请传递newline =''的参数（用于通用识别，以便在读取/迭代时断行，但不转换行结尾）或换行='\ n' （例如）仅表示\ n被识别为完全结束的行，并且再次不执行行结尾的转换。要正确处理某些文件格式，需要传递newline =''; csv模块执行自己的行结束处理，newline =''确保在到达csv阅读器之前没有信息丢失。
#1
7
Python 3's open defaults to universal newlines mode (newline=None), while Python 2's open only enables universal newlines mode if the mode string include U.
Python 3的open默认为通用换行模式（newline = None），而Python 2的open仅在模式字符串包含U时启用通用换行模式。
In universal newlines mode, a sequence \r (old Mac), \n (UNIX) or \r\n (DOS/Windows) are all recognized as newlines, and automatically converted to \n so line endings have a consistent representation to simplify string manipulation.
在通用换行模式下，序列\ r \ n（旧Mac），\ n（UNIX）或\ r \ n（DOS / Windows）都被识别为换行符，并自动转换为\ n，因此行结尾具有一致的表示形式以简化字符串操作。
If you want universal newlines in Python 2, you can either use the mode string to enable it or use io.open, which is a near exact equivalent of Python 3's built-in open (io.open on Python 3 is just another way to say open).
如果你想在Python 2中使用通用换行符，你可以使用模式字符串来启用它，或者使用io.open，它几乎完全等同于Python 3的内置开放（Python 3上的io.open只是另一种方式说开放）。
If you want to disable universal newlines handling on Python 3, pass open an argument of newline='' (for universal recognition for the purposes of breaking lines when reading/iterating, but no translation of line endings) or newline='\n' (for example) to mean only \n is recognized as a line ending at all, and again, no translation of line endings is performed. Passing newline='' is required to properly handle certain file formats; the csv module performs its own line ending handling, and newline='' ensures no information is lost before it reaches the csv reader.
如果要在Python 3上禁用通用换行符处理，请传递newline =''的参数（用于通用识别，以便在读取/迭代时断行，但不转换行结尾）或换行='\ n' （例如）仅表示\ n被识别为完全结束的行，并且再次不执行行结尾的转换。要正确处理某些文件格式，需要传递newline =''; csv模块执行自己的行结束处理，newline =''确保在到达csv阅读器之前没有信息丢失。