“语法”是什么：在呼叫到“ print”中缺少括号。在python中的意思？

发布于 2025-02-13 23:50:54 字数 551 浏览 2 评论 0原文

当我尝试在Python中使用打印语句时，它给了我这个错误：

>>> print "Hello, World!"
  File "<stdin>", line 1
    print "Hello, World!"
                        ^
SyntaxError: Missing parentheses in call to 'print'

这是什么意思？

请参阅获得使用关键字参数end end end yend =''的syntaxerror。

_{参见 python 3打印括号用于解决方法，并确认打印不能像的一样工作，就像python 3中的语句。}

原文

When I try to use a print statement in Python, it gives me this error:

>>> print "Hello, World!"
  File "<stdin>", line 1
    print "Hello, World!"
                        ^
SyntaxError: Missing parentheses in call to 'print'

What does that mean?

_{See Getting SyntaxError for print with keyword argument end=' ' for the opposite problem.}

_{See Python 3 print without parenthesis for workarounds, and confirmation that print cannot be made to work like a statement in Python 3.}

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╰ゝ天使的微笑 2025-02-20 23:50:54

错误消息 SyntaxError：当您尝试使用Python 3语法与Python 2 Print语句时，会在“ print” 呼叫中丢失括号。

示例：
>

~~print "Hello, World!"~~

在Python 3中，打印语句被print（）函数替换，需要围绕要打印的值括号。

解决方案

print("Hello, World!")

在Python 3中，打印语句被打印（）函数代替，需要围绕要打印的值括号。

>>> print("Hello, World!")
Hello, World!

在Python 3的早期版本中，解释器只是报告了通用语法错误，而没有提供任何可能出现的有用提示：

>>> print "Hello, World!"
  File "<stdin>", line 1
    print "Hello, World!"
                        ^
SyntaxError: invalid syntax

而对于，为什么为什么在Python 3中的功能与语句的基本形式无关，而是与您如何做更复杂的事情，例如用后续空间打印多个项目，而不是结束行。

在Python 2中：

>>> import sys
>>> print >> sys.stderr, 1, 2, 3,; print >> sys.stderr, 4, 5, 6
1 2 3 4 5 6

在Python 3中：

>>> import sys
>>> print(1, 2, 3, file=sys.stderr, end=" "); print(4, 5, 6, file=sys.stderr)
1 2 3 4 5 6

从2017年9月的Python 3.6.3发行开始，已经更新了与Python 2.x 2.x打印语法相关的一些错误消息，以推荐其Python 3.x 3.x对应物：

>>> print "Hello!"
  File "<stdin>", line 1
    print "Hello!"
                 ^
SyntaxError: Missing parentheses in call to 'print'. Did you mean print("Hello!")?

自从“自“自从”呼叫打印“ case是一个编译时间语法错误，因此可以访问原始源代码，它可以在建议的其余部分中包含全文替代品。但是，目前尚未尝试制定适当的报价来围绕该表达式放置（这不是不可能的，只是足够复杂，以至于尚未完成）。

typeError为正确的换档运算符筹集的也已被定制：

>>> print >> sys.stderr
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unsupported operand type(s) for >>: 'builtin_function_or_method' and '_io.TextIOWrapper'. Did you mean "print(<message>, file=<output_stream>)"?

由于代码运行时会增加此错误，而不是在编译时，它无法访问原始源代码，并且因此，在建议的替换表达式中使用meta-variobles（＆lt; message＆gt; and ＆lt; output_stream＆gt; ）打字。与语法错误案例不同，在自定义右移动错误消息中围绕Python表达式的引号很简单。

The error message SyntaxError: Missing parentheses in call to 'print' occurs when you attempt to use Python 3 syntax with the Python 2 print statement.

Example:

~~print "Hello, World!"~~

In Python 3, the print statement was replaced with a print() function, requiring parentheses around the value to be printed.

Solution

print("Hello, World!")

In Python 3, the print statement was replaced with a print() function, requiring parentheses around the value to be printed.

>>> print("Hello, World!")
Hello, World!

In earlier versions of Python 3, the interpreter just reports a generic syntax error, without providing any useful hints as to what might be going wrong:

>>> print "Hello, World!"
  File "<stdin>", line 1
    print "Hello, World!"
                        ^
SyntaxError: invalid syntax

As for why print became an ordinary function in Python 3, that didn't relate to the basic form of the statement, but rather to how you did more complicated things like printing multiple items to stderr with a trailing space rather than ending the line.

In Python 2:

>>> import sys
>>> print >> sys.stderr, 1, 2, 3,; print >> sys.stderr, 4, 5, 6
1 2 3 4 5 6

In Python 3:

>>> import sys
>>> print(1, 2, 3, file=sys.stderr, end=" "); print(4, 5, 6, file=sys.stderr)
1 2 3 4 5 6

Starting with the Python 3.6.3 release in September 2017, some error messages related to the Python 2.x print syntax have been updated to recommend their Python 3.x counterparts:

>>> print "Hello!"
  File "<stdin>", line 1
    print "Hello!"
                 ^
SyntaxError: Missing parentheses in call to 'print'. Did you mean print("Hello!")?

Since the "Missing parentheses in call to print" case is a compile time syntax error and hence has access to the raw source code, it's able to include the full text on the rest of the line in the suggested replacement. However, it doesn't currently try to work out the appropriate quotes to place around that expression (that's not impossible, just sufficiently complicated that it hasn't been done).

The TypeError raised for the right shift operator has also been customised:

>>> print >> sys.stderr
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unsupported operand type(s) for >>: 'builtin_function_or_method' and '_io.TextIOWrapper'. Did you mean "print(<message>, file=<output_stream>)"?

Since this error is raised when the code runs, rather than when it is compiled, it doesn't have access to the raw source code, and hence uses meta-variables (<message> and <output_stream>) in the suggested replacement expression instead of whatever the user actually typed. Unlike the syntax error case, it's straightforward to place quotes around the Python expression in the custom right shift error message.

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好多鱼好多余 2025-02-20 23:50:54

不幸的是，旧的 XKCD漫画不再完全最新。

你

print("Hello, World!")

。

Unfortunately, the old xkcd comic isn't completely up to date anymore.

Since Python 3.0 you have to write:

print("Hello, World!")

And someone has still to write that antigravity library :(

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乖乖 2025-02-20 23:50:54

语法从Python 2到Python 3发生了变化。
在Python 2中，

print "Hello, World!"

将起作用，但在Python 3中使用括号，因为

print("Hello, World!")

这是与Scala相同的语法，靠近Java。

There is a change in syntax from Python 2 to Python 3.
In Python 2,

print "Hello, World!"

will work but in Python 3, use parentheses as

print("Hello, World!")

This is equivalent syntax to Scala and near to Java.

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扮仙女 2025-02-20 23:50:54

在python 3.x中，print现在是函数，而不是语句，如2.x。

因此，打印由调用作为函数使用，因此需要括号：

python 2.x 2.x ：打印” “

python 3.x ：print（“戒指之王”）

有多个优点

制作print一个函数打印多个值时更灵活（现在是对函数的参数）。特别是，它允许参数splatting ：

>>> items = ['foo', 'bar', 'baz']
>>> print(*items, sep='+')
foo+bar+baz

可以通过简单地编写呼叫print> print> print> princt 的行为一个名为打印的新功能。对于打印语句，这是不可能的。

In Python 3.x, print is now a function, rather than a statement as it was in 2.x.

Therefore, print is used by calling it as a function, and thus parentheses are needed:

Python 2.x: print "Lord of the Rings"

Python 3.x: print("Lord of the Rings")

There are multiple advantages to making print a function:

The print function offers more flexibility when printing multiple values (which are now arguments to the function). In particular, it allows for argument splatting:

>>> items = ['foo', 'bar', 'baz']
>>> print(*items, sep='+')
foo+bar+baz

The behavior of calls to print can be replaced by simply writing a new function named print. This would be impossible with the print statement.

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≈。彩虹 2025-02-20 23:50:54

如果您的代码在Python 2和3中都可以使用，则可以通过在程序开始时加载它来实现此目标：

from __future__ import print_function   # If code has to work in Python 2 and 3!

然后，您可以以Python 3方式打印：

print("python")

如果您想打印某些东西而不创建新行 - 您可以可以这样做：

for number in range(0, 10):
    print(number, end=', ')

If your code should work in both Python 2 and 3, you can achieve this by loading this at the beginning of your program:

from __future__ import print_function   # If code has to work in Python 2 and 3!

Then you can print in the Python 3 way:

print("python")

If you want to print something without creating a new line - you can do this:

for number in range(0, 10):
    print(number, end=', ')

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陈年往事 2025-02-20 23:50:54

在Python 3中，您只能打印为：

print("STRING")

但是在Python 2中，括号不需要。

In Python 3, you can only print as:

print("STRING")

But in Python 2, the parentheses are not necessary.

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不知所踪 2025-02-20 23:50:54

我还可以补充说，我了解有关python2.7和python3之间的语法更改的一切，并且我的代码被正确地写成print（“ String”）甚至
print（f“ string”） ...

但是经过一段时间的调试，我意识到我的bash脚本正在调用python，例如：

python file_name.py

默认情况下使用python2.7来调用我的python脚本，这给出了错误。因此，我将bash脚本更改为：

python3 file_name.py

当然使用python3来运行修复错误的脚本。

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无远思近则忧 2025-02-20 23:50:54

print（'Hello，World！'）

您正在使用Python 3，在打印时需要支架。

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如梦亦如幻 2025-02-20 23:50:54

因此，我遇到了这个错误

from trp import BoundingBox, Document
File "C:\Users\Kshitij Agarwal\AppData\Roaming\Python\Python39\site-packages\trp\__init__.py", line 31
print ip
      ^ 
SyntaxError: Missing parentheses in call to 'print'. Did you mean print(ip)?

，这是一个Python软件包错误，其中使用了Python2，您可能正在Python3上运行此错误。

一种解决方案可能是将python2 转换为Python3打印 print> print（sothings）在包装文件夹中的每一行中的每一行，这不是一个好主意

So I was getting this error

from trp import BoundingBox, Document
File "C:\Users\Kshitij Agarwal\AppData\Roaming\Python\Python39\site-packages\trp\__init__.py", line 31
print ip
      ^ 
SyntaxError: Missing parentheses in call to 'print'. Did you mean print(ip)?

This is a Python package error, in which Python2 has been used and you are probably running this on Python3.

One solution could be to convert Python2 print something to Python3 print(something) for every line in each file in the package folder, which is not a good idea????. I mean, you can do it but still there are better ways.

To perform the same task, there is a package named 2to3 in Python which converts Python2 scripts to Python3 scripts. To install it, execute the ???? command in terminal..

pip install 2to3

Then change the directory in terminal to the location where the package files are present, in my case - C:\Users\Kshitij Agarwal\AppData\Roaming\Python\Python39\site-packages\trp

Now execute the command ????