Syntaxerror unexpected character after line continuation character что значит
SyntaxError: unexpected character after line continuation character
In python, the error SyntaxError: unexpected character after line continuation character occurs when the escape character is misplaced in the string or characters added after line continuation character. The “\” escape character is used to indicate continuation of next line. If any characters are found after the escape character “\”, The python interpreter will throw the error unexpected character after line continuation character in python language.
The string in python contains escape sequence characters such as \n, \0, \t etc. If you miss or delete quotes in the string, the escape character “\” in the string is the end of the current line. If any characters are found after the “\” is considered invalid. Python therefore throws this error SyntaxError: Unexpected character after line continuation character.
SyntaxError: unexpected character after line continuation character
Here, we see the common mistakes that causes this SyntaxError: Unexpected character after line continuation character error and how to fix this error. The error would be thrown as like below.
Root Cause
The back slash “\” is considered to be th end of line in python. If any characters are added after the back slash is deemed invalid. The back slash “\” is also used as an escape sequence character in the python string. For instance “\n” is a new line character. “\t” is a tab in python.
If the quotation in the string is missing or deleted, the escape character “\” will be treated as the end of the line. The characters added after that will be considered invalid. Therefore, Python throws this SyntaxError: unexpected character after line continuation character error
How to reproduce this error
If any characters are added after the back slash “\”, they will be treated as invalid. Adding the python code after the end of line character “\” will throw this error SyntaxError: unexpected character after line continuation character. In this example, the character “n” in the “\n” is considered invalid.
Output
Solution 1
The python string should be enclosed with single or double quotes. Check the string that has been properly enclosed with the quotations. If a quotation is missed or deleted, correct the quotation. This is going to solve this error. The code above will be fixed by adding the quotation in “\n”.
Output
Solution 2
If you want to add the “\n” as a character with no escape sequence operation, then “r” should be prefixed along with the string. This will print the characters as specified within the string. The code below will be printed as “\n” instead of a new line character.
Output
Solution 3
If a character is added after the end of the line, the character should be moved to the next line. When the copy and paste operation is performed, the new line characters are missing. Fixing the intent of the code will resolve this SyntaxError: unexpected character after line continuation character error.
Output
Solution
Output
Solution 4
If a white space is added after the end of the “\” line character, it should be removed. The character is not visible in the code. If the python interpreter throws this error and no characters are visible, a whitespace must be availabe after that. Removing all whitespace after the end of the “\” character will resolve this error.
9 Examples of Unexpected Character After Line Continuation Character (Python)
This is about the Python syntax error unexpected character after line continuation character.
This error occurs when the back slash character \ is used incorrectly.
So if you want to understand this error in Python and how to solve it, then you’re in the right place.
Table of Contents
SyntaxError: Unexpected Character After Line Continuation Character in Python
So you got SyntaxError: unexpected character after line continuation character?—don’t be afraid this article is here for your rescue and this error is easy to fix:
Syntax errors are usually the easiest to solve because they appear immediately after the program starts and you can see them without thinking about it much. It’s not like some logical rocket science error.
However, when you see the error SyntaxError: unexpected character after line continuation character for the first time, you might be confused:
What Is a Line Continuation Character in Python?
A line continuation character is just a backslash \—place a backlash \ at the end of a line, and it is considered that the line is continued, ignoring subsequent newlines.
You can use it for explicit line joining, for example. You find more information about explicit line joining in the official documentation of Python. Another use of the backslash \ is to escape sequences—more about that further below.
However, here is an example of explicit line joining:
So as you can see the output is: This is a huge line. It is very large, but it needs to be printed on the screen in one line. For this, the backslash character is used. No line breaks.
The backslash \ acts like a glue and connects the strings to one string even when they are on different lines of code.
When to Use a Line Continuation Character in Phython?
You can break lines of code with the backslash \ for the convenience of code readability and maintainability:
The PEP 8 specify a maximum line length of 79 characters—PEP is short for Python Enhancement Proposal and is a document that provides guidelines and best practices on how to write Python code.
However, you don’t need the backslash \ when the string is in parentheses. Then you can just do line breaks without an line continuation character at all. Therefore, in the example above, you didn’t need to use the backslash character, as the entire string is in parentheses ( … ).
However, in any other case you need the backslash \ to do a line break. For example (the example is directly from the official Python documentation):
Why all that talking about this backslash? Here is why:
The error SyntaxError: unexpected character after line continuation character occurs when the backslash character is incorrectly used. The backslash is the line continuation character mentioned in the error!
Examples of “SyntaxError: Unexpected Character After Line Continuation Character” in Python
Here are examples of the character after line continuation character error:
Example #1
The error occurs when you add an end-of-line character or line continuation character as a list item:
Easy to fix—just put the backslash \ in quotes:
Example #2
You want to do a line break after printing something on the screen:
Easy to fix, again—the backslash \ goes in to quotes:
Perhaps you want to add a new line when printing a string on the screen, like this.
Example #3
Mistaking the slash / for the backslash \—the slash character is used as a division operator:
Another easy syntax error fix—just replace the backslash \ with the slash /:
Example #5
However, when a string is rather large, then it’s not always that easy to find the error on the first glance.
Here is an example from Stack Overflow:
The line of code contains several backslashes \—so you need to take a closer look.
Split the line of code into logical units and put each unit on separate line of code. This simplifies the debugging:
Now you can easily see where the backslash \ is missing—with a sharp look at the code itself or through the debugger output. A backslash \ misses after the 1.5 in line of code #4.
Example #6
Another common case of this error is writing the paths to Windows files without quotes. Here is another example from Stack Overflow:
The full path to the file in code of line #1 must be quoted “”. Plus, a colon : is to be placed after the drive letter in case of Windows paths:
The Backslash \ as Escape Character in Python
The backslash \ is also an escape character in Python:
Use the backslash \ to escape service characters in a string.
For example, to escape a tab or line feed service character in a string. And because the backslash \ is a service character on its own (remember, it’s used for line continuation), it needs to be escaped too when used in a string—\\.
This is why in the last example the path contains double backslashes \\ instead of a single backslash \ in line of code #1.
However, you don’t need any escapes in a string when you use a raw string. Use the string literal r to get a raw string. Then the example from above can be coded as:
No backslash \ escapes at all, yay!
Another use case for an escape are Unicode symbols. You can write any Unicode symbol using an escape sequence.
For example, an inverted question mark ¿ has the Unicode 00BF, so you can print it like this:
Additional Examples of “SyntaxError: Unexpected Character After Line Continuation Character” in Python
Here are more common examples of the unexpected character after line continuation character error:
Example #7
Often, you don’t have a specific file or folder path and have to assemble it from parts. You can do so via escape sequences \\ and string concatenations \. However, this manual piecing together regularly is the reason for the unexpected character after line continuation character error.
But the osmodule to the rescue! Use the path.join function. The path.join function not only does the path completion for you, but also determines the required separators in the path depending on the operating system on which you are running your program.
#os separator examples?
Example #8
You can get the line continuation error when you try to comment out # a line after a line continuation character \—you can’t do that in this way:
Remember from above that within parenthesis () an escape character is not needed? So put the string in parenthesis (), easy as that—and voila you can use comments # where ever you want.
You can put dummy parentheses, simply for hyphenation purposes:
Example #9
Another variation of the unexpected character after line continuation character error is when you try to run a script from the Python prompt. Here is a script correctly launched from the Windows command line:
However, if you type python first and hit enter, you will be taken to the Python prompt.
Here, you can directly run Python code such as print(“Hello, World!”). And if you try to run a file by analogy with the Windows command line, you will get an error:
синтаксис ошибка: «unexpected character after line continuation character in python» математике
У меня возникли проблемы с этой программой Python, которую я создаю, чтобы делать математику, разрабатывать и так далее решения, но я получаю syntaxerror: «unexpected character after line continuation character in python»
Использование python 2.7.2
6 ответов
Я очень новичок в Python. Я строю строку, которая является не чем иным, как путем к сетевому местоположению следующим образом. Но он выводит ошибку: Python unexpected character after line continuation character. Пожалуйста, помогите. Я видел этот пост, но не уверен, что он применим к моему.
У меня есть скрипт Python, который имеет класс, определенный с помощью этого метода: @staticmethod def _sanitized_test_name(orig_name): return re.sub(r'[`‘’\]*’, », re.sub(r'[\r\n\/\:\?\ \|\*\%]*’, », orig_name.encode(‘utf-8’))) Я могу запустить скрипт из командной строки просто отлично.
Если вы хотите написать дословную обратную косую черту в строке, экранируйте ее, удвоив: «\\»
В своем коде вы используете его дважды:
Кроме того, обратная косая черта имеет особое значение внутри строки Python. Либо избежать его с помощью другой обратной косой черты:
или используйте необработанную строку
Вы должны нажать клавишу enter после символа продолжения
Примечание: Пробел после символа продолжения приводит к ошибке
Я думаю, чтобы напечатать строку, которую вы хотели, я думаю, вам понадобится этот код:
И это более читаемая версия вышеизложенного (с использованием метода форматирования):
Ну, и что ты пытаешься сделать? Если вы хотите использовать разделение, используйте»/», а не «\». Если это что-то другое, объясните это немного подробнее, пожалуйста.
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Я пытаюсь переименовать ‘\’ С ‘\\’, используя приведенный ниже код, но он показывает ошибку как SyntaxError: unexpected character after line continuation character String = C\users\stat.csv.
I am getting an unexpected character after line continuation character error
I am getting an unexpected character after line continuation character error in this line
could someone tell me what that means and how to fix it? thanks
2 Answers 2
You’ve forgot to use quotes around many items on this line:
And another way to format is to use str.format like this:
Ashwini’s answer explains why your code gives the error it does.
But there’s a much simpler way to do this. Instead of printing a bunch of strings separated by commas like this, just put the strings together:
(I also fixed everything to fit on an 80-column screen, which is a standard for good reasons—for one thing, it’s actually readable on things like StackOverflow; for another, it makes it much more obvious that your code doesn’t actually line up the way you wanted it to…)
In this case, it would probably be even better to use three separate print calls. Then you don’t need those \n characters in the first place:
Meanwhile, since you’re already using the format function, you should have no trouble learning about the format method, which makes things even simpler. Again, you can use three separate statements—but in this case, maybe a multi-line (triple-quoted) string would be easier to read:
See the tutorial section on Fancier Output Formatting for more details on all of this.
How to avoid SyntaxError: unexpected character after line continuation character
I have tried writing the \t as \\t but couldnt avoid the syntax error.
ADDITIONAL NOTE: Here is the sample input:
and this is the sample output:
And I want to make one big output by using the for loop over about 100 other files like the sample input
2 Answers 2
Here’s a pure-Python reimplementation.
The Awk script too would benefit from checking for GO: already in the Awk part before printing anything at all.
Notice that this fixes several bugs in your Python code as well.
You were also not doing anything with the data you read in, and the shell pipeline was not receiving any input, either.
Your code would write Genome GO_term once per input file; I preserved that logic, but am guessing perhaps you didn’t really want it to work that way. The grep in your original would discard this output; of course, if you really don’t want it, don’t print it in the first place.
Similarly, I’ll point out that the uniq would run once per input file, so if multiple input files contained the same value, you would get duplicates. If that’s not what you want, creating the empty seen set outside the for loop instead makes it global.
. This would not have been too hard to fix in a shell script, either; just run Awk on all the input files in one go. Actually then you would not need Python here at all (or, as noted above, grep ).
Note also that uniq only removes adjacent identical lines. In the Python code, I assumed you really want each output line to be unique, but this should be easy to change back (just remember the previous printed value, and don’t print if this one is identical). Conversely, it would not be hard to refactor the Awk script to not print repeats using very similar logic, though of course the Awk syntax will be quite different from how it looks in Python.
To contrast these two approaches, note how much more succinct the Awk code is. Even if you extended it to quadruple its size and complexity, it would still be quite small and easy to understand. But then that’s roughly the limit of what makes sense to do in Awk; if you plan to make this part of a bigger, more complex program, Python is more suitable for that. Also, the Python code, in all its explicitness, is quite easy to understand even if you don’t use the language every day. I’m afraid the same cannot be said about Awk. The explicit structure of the Python code also makes it easy to see which part might need to be changed if you reveal or discover new requirements.