python 这段代码是什么意思：“打印>> sys.stderr”
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What does this code mean: "print >> sys.stderr"
提问by zjm1126
print >> sys.stderr, "Error in atexit._run_exitfuncs:"
Why print '>>' in front of sys.stderr?
为什么要在前面打印“>>” sys.stderr？
Thanks.
谢谢。
回答by iamamac
This syntax means writes to a file object (sys.stderrin this case) instead of standard output. [Link]
此语法意味着写入文件对象（sys.stderr在本例中）而不是标准输出。[关联]
In Python 3.0, printbecomes a function instead of a statement: [Link]
在 Python 3.0 中，print变成函数而不是语句：[链接]
print("Error in atexit._run_exitfuncs:", file=sys.stderr)
回答by James Thompson
From the Python documentation:
print also has an extended form, defined by the second portion of the syntax described above. This form is sometimes referred to as “print chevron.” In this form, the first expression after the >> must evaluate to a “file-like” object, specifically an object that has a write() method as described above. With this extended form, the subsequent expressions are printed to this file object. If the first expression evaluates to None, then sys.stdout is used as the file for output.
print 也有一个扩展形式，由上述语法的第二部分定义。这种形式有时被称为“印刷 V 形”。在这种形式中，>> 之后的第一个表达式必须评估为“类文件”对象，特别是具有上述 write() 方法的对象。使用此扩展形式，后续表达式将打印到此文件对象。如果第一个表达式的计算结果为 None，则 sys.stdout 用作输出文件。
