Вывод без новой строки или пробела в Python
Сегодня я рассмотрю различные способы печати значений без возврата символа новой строки или каретки. Это очень полезная статья!
Введение
Функция print в Python добавляет новую строку к выходным данным при отображении в терминале. Если вы не хотите, чтобы ваше сообщение отображалось с новыми строками или пробелами, то как вы можете изменить поведение функции print?
Этого можно легко достичь, изменив значения по умолчанию параметров sep и end функции print.
Печать без новой строки
До версии Python 2.x, print было зарезервированным ключевым словом, которое действует как специальный оператор. Начиная с Python версии 3.x, команда print превратилась в функцию.
Эта версия print способна принимать следующие аргументы:
Значения (value1, value2), упомянутые выше, могут быть любой строкой или любым из типов данных, таких как list, float, string и так далее. Другие аргументы включают разделитель sep, используемый для разделения значений, заданных в качестве аргументов, в то время как аргумент end по умолчанию является символом новой строки «\n». Именно по этой причине при каждом вызове функции print курсор перемещается на следующую строку.
В Python 3.x самый простой способ печати без новой строки — это установить аргумент end в виде пустой строки, то есть » «. Теперь, попробуйте выполнить следующий фрагмент кода в интерпретаторе Python:
Интерпретатор выдаст следующее:
Мы печатаем две строки, поэтому Python будет использовать значение «sep», пустое пространство по умолчанию, чтобы напечатать их вместе. Python также добавляет символ новой строки в конце, поэтому приглашение интерпретатора переходит в конечную строку.
Теперь измените предыдущее утверждение так, чтобы оно выглядело следующим образом:
Выполнив его в интерпретаторе, вы получите результат, напоминающий:
Здесь произошло следующее: разделитель между двумя строками теперь также включает точку с запятой. Приглашение интерпретатора также появляется в той же строке, потому что мы удалили автоматически добавляемый символ новой строки.
Печать без новой строки в Python 2.X
Для более ранних версий Python (старше 3, но больше 2.6), вы можете импортировать print_function из модуля __future__. Это переопределит существующее ключевое слово print с помощью функции print, как показано ниже:
Вот как вы можете использовать функцию print от Python версии 3 в Python 2.x.
Использование stdout.write
Модуль sys имеет встроенные функции для записи непосредственно в файл или в TTY. Эта функция доступна для версий Python 2.x и 3.x. Мы можем использовать метод write объекта stdout модуля sys для печати на консоли следующим образом:
Хотя это дает результат того, чего мы пытаемся достичь, существует довольно много различий между функцией write и функцией print. Функция print может печатать несколько значений одновременно, может принимать нестроковые значения и более дружелюбна к разработчикам.
Заключение
В этой статье я рассмотрел различные способы печати значений без возврата символа новой строки/каретки. Эта стратегия может оказаться весьма полезной при печати элементов в выходных данных алгоритмов, таких как двоичное дерево или печать содержимого списка рядом друг с другом.
How to Print Without a Newline in Python
In this Python tutorial, we will discuss how to print without a newline in Python. Also we will different ways to print without newline in loop in Python.
When learning Python, one of the first things you learn is how to use the print() function to output data to the console. By default, the print() function appends a newline character at the end of the output. However, there might be situations where you want to print without a newline, let us see different ways to print in the same line in Python.
Table of Contents
The print() function in Python
The print() function in Python is used to output data to the console. By default, it appends a newline character (‘\n’) at the end of the output, which causes the next printed output to appear on a new line. Here’s an example:
Output:
Print Without a Newline in Python using the ‘end’ parameter
You can use the ‘end’ parameter within the Python print() function to change the default behavior of appending a newline character at the end of the output. The ‘end’ parameter allows you to specify a different string to be appended at the end of the output.
Example:
Output:
Python print without newline using the ‘sep’ parameter
The ‘sep’ parameter can be used to print multiple arguments without a newline in between in Python. By default, the ‘sep’ parameter has a space character (‘ ‘) as its value. You can change this value to an empty string to remove the space between printed arguments.
Example:
Output:
Python print without newline using the sys.stdout.write() method
Another way to print without a newline in Python is by using the write() method of the sys.stdout object. This method writes a string to the console without appending a newline character.
Example:
Output:
Python print without newline in loop
Now, let us see a few ways to print without a newline in a loop in Python.
In Python, when printing inside a loop, the default behavior is to append a newline character at the end of each printed output. However, there might be situations where you want to print without a newline while iterating through a loop. Here, we will discuss how to print without a newline in a loop using various methods.
Using the ‘end’ parameter in a loop
The ‘end’ parameter within the print() function can be used to change the default behavior of appending a newline character at the end of the output. When printing inside a loop, you can use the ‘end’ parameter to control the output format.
Example-1: Print numbers from 1 to 5 in a single line
Output:
Example 2: Print a list of names separated by a comma
Using the ‘sep’ parameter in a loop
The ‘sep’ parameter in the print() function allows you to control the separator between multiple arguments. When printing inside a loop, you can use the ‘sep’ parameter to achieve the desired output format.
Example: Print elements of a list separated by a comma
Output:
Using sys.stdout.write() in a loop
Another way to print without a newline in a loop is by using the write() method of the sys.stdout object. This method writes a string to the console without appending a newline character.
Example: Print numbers from 1 to 5 in a single line
Output:
We have learned different methods to print without a newline in a loop in Python. We covered how to use the ‘end’ and ‘sep’ parameters of the print() function, as well as the sys.stdout.write() method.
Conclusion
We have also learned different methods to print without a newline in Python. We covered how to use the ‘end’ and ‘sep’ parameters of the print() function, as well as the sys.stdout.write() method.
You may also like:
I am Bijay Kumar, a Microsoft MVP in SharePoint. Apart from SharePoint, I started working on Python, Machine learning, and artificial intelligence for the last 5 years. During this time I got expertise in various Python libraries also like Tkinter, Pandas, NumPy, Turtle, Django, Matplotlib, Tensorflow, Scipy, Scikit-Learn, etc… for various clients in the United States, Canada, the United Kingdom, Australia, New Zealand, etc. Check out my profile.
Python: How to Print Without Newline? (The Idiomatic Way)
Python is one of the easiest programming languages to learn.
One of the first programs that you write when you start learning any new programming language is a hello world program.
A hello world program in python looks like this
It is that easy!
Just one line and boom you have your hello world program.
In Python 3, print() is a function that prints out things onto the screen (print was a statement in Python 2).
As you can see, it is a very simple function.
Yet there is one thing that is really annoying about this function.
It automatically prints a newline ‘\n’ at the end of the line!
Let’s take a look at this example
As you can notice, the two strings are not printed one after the other on the same line but on separate lines instead.
Even though this might be what you actually want, but that’s not always the case.
if you’re coming from another language, you might be more comfortable with explicitly mentioning whether a newline should be printed out or not.
For example in Java, you have to explicitly indicate your desire to print a newline by either using the println function or typing the newline character (\n) inside your print function:
So what should we do if we want no newline characters in python?
Let’s jump right into the solution!
The Solution
Printing with no newlines in Python 3
Python 3 provides the simplest solution, all you have to do is to provide one extra argument to the print function.
You can use the optional named argument end to explicitly mention the string that should be appended at the end of the line.
Whatever you provide as the end argument is going to be the terminating string.
So if you provide an empty string, then no newline characters, and no spaces will be appended to your input.
Printing with no newlines in Python 2
In python 2, the easiest way to avoid the terminating newline is to use a comma at the end of your print statement
As you can see, even though there was no newlines, we still got a space character between the two print statements.
If you actually needed a space, then this is the simplest and most straightforward way to go.
But what if you want to print without a space or newline?
In this you can, you should use the all-powerful sys.stdout.write function from the sys module.
This function will only print whatever you explicitly tell it to print.
There are no terminating strings.
There is no magic!
Let’s take an example
Conclusion
In Python 3, you can use the named end argument in the print function and assign an empty string to this argument to prevent the terminating newline.
How to print without a newline or space
Either a newline or a space is added between each value. How can I avoid that, so that the output is . instead? In other words, how can I "append" strings to the standard output stream?
27 Answers 27
In Python 3, you can use the sep= and end= parameters of the print function:
To not add a newline to the end of the string:
To not add a space between all the function arguments you want to print:
You can pass any string to either parameter, and you can use both parameters at the same time.
If you are having trouble with buffering, you can flush the output by adding flush=True keyword argument:
Python 2.6 and 2.7
From Python 2.6 you can either import the print function from Python 3 using the __future__ module:
which allows you to use the Python 3 solution above.
However, note that the flush keyword is not available in the version of the print function imported from __future__ in Python 2; it only works in Python 3, more specifically 3.3 and later. In earlier versions you’ll still need to flush manually with a call to sys.stdout.flush() . You’ll also have to rewrite all other print statements in the file where you do this import.
You may also need to call
to ensure stdout is flushed immediately.
For Python 2 and earlier, it should be as simple as described in Re: How does one print without a CR? by Guido van Rossum (paraphrased):
Is it possible to print something, but not automatically have a carriage return appended to it?
Yes, append a comma after the last argument to print. For instance, this loop prints the numbers 0..9 on a line separated by spaces. Note the parameterless "print" that adds the final newline:
Note: The title of this question used to be something like "How to printf in Python"
Since people may come here looking for it based on the title, Python also supports printf-style substitution:
And, you can handily multiply string values:
Use the Python 3-style print function for Python 2.6+ (it will also break any existing keyworded print statements in the same file).
To not ruin all your Python 2 print keywords, create a separate printf.py file:
Then, use it in your file:
More examples showing the printf style:
How to print on the same line:
The print function in Python 3.x has an optional end parameter that lets you modify the ending character:
There’s also sep for separator:
If you wanted to use this in Python 2.x just add this at the start of your file:
Using functools.partial to create a new function called printf:
It is an easy way to wrap a function with default parameters.
In Python 3+, print is a function. When you call
Python translates it to
You can change end to whatever you want.
In Python 2.x, you can just add , at the end of the print function, so it won’t print on a new line.
Python 3:
Python 2.6+:
Python <=2.5:
If extra space is OK after each print, in Python 2:
Misleading in Python 2 — avoid:
In general, there are two ways to do this:
Print without a newline in Python 3.x
Append nothing after the print statement and remove ‘\n’ by using end=» , as:
Another Example in Loop:
Print without a newline in Python 2.x
Adding a trailing comma says: after print, ignore \n .
Another Example in Loop:
You can visit this link.
I recently had the same problem.
I solved it by doing:
This works on both Unix and Windows, but I have not tested it on Mac OS X.
You can do the same in Python 3 as follows:
And execute it with python filename.py or python3 filename.py .
Many of these answers seem a little complicated. In Python 3.x you simply do this:
The default value of end is «\n» . We are simply changing it to a space or you can also use end=»» (no space) to do what printf normally does.
You want to print something in the for loop right; but you don’t want it print in new line every time.
But you want it to print like this: hi hi hi hi hi hi right.
Just add a comma after printing "hi".
You will notice that all the above answers are correct. But I wanted to make a shortcut to always writing the " end=» " parameter in the end.
You could define a function like
It would accept all the number of parameters. Even it will accept all the other parameters, like file, flush, etc. and with the same name.
lenooh satisfied my query. I discovered this article while searching for ‘python suppress newline’. I’m using IDLE 3 on Raspberry Pi to develop Python 3.2 for PuTTY.
I wanted to create a progress bar on the PuTTY command line. I didn’t want the page scrolling away. I wanted a horizontal line to reassure the user from freaking out that the program hasn’t cruncxed to a halt nor been sent to lunch on a merry infinite loop — as a plea to ‘leave me be, I’m doing fine, but this may take some time.’ interactive message — like a progress bar in text.
The print(‘Skimming for’, search_string, ‘\b! .001’, end=») initializes the message by preparing for the next screen-write, which will print three backspaces as ⌫⌫⌫ rubout and then a period, wiping off ‘001’ and extending the line of periods.
After search_string parrots user input, the \b! trims the exclamation point of my search_string text to back over the space which print() otherwise forces, properly placing the punctuation. That’s followed by a space and the first ‘dot’ of the ‘progress bar’ which I’m simulating.
Unnecessarily, the message is also then primed with the page number (formatted to a length of three with leading zeros) to take notice from the user that progress is being processed and which will also reflect the count of periods we will later build out to the right.
The progress bar meat is in the sys.stdout.write(‘\b\b\b.’+format(page, ’03’)) line. First, to erase to the left, it backs up the cursor over the three numeric characters with the ‘\b\b\b’ as ⌫⌫⌫ rubout and drops a new period to add to the progress bar length. Then it writes three digits of the page it has progressed to so far. Because sys.stdout.write() waits for a full buffer or the output channel to close, the sys.stdout.flush() forces the immediate write. sys.stdout.flush() is built into the end of print() which is bypassed with print(txt, end=» ) . Then the code loops through its mundane time intensive operations while it prints nothing more until it returns here to wipe three digits back, add a period and write three digits again, incremented.
The three digits wiped and rewritten is by no means necessary — it’s just a flourish which exemplifies sys.stdout.write() versus print() . You could just as easily prime with a period and forget the three fancy backslash-b ⌫ backspaces (of course not writing formatted page counts as well) by just printing the period bar longer by one each time through — without spaces or newlines using just the sys.stdout.write(‘.’); sys.stdout.flush() pair.
Please note that the Raspberry Pi IDLE 3 Python shell does not honor the backspace as ⌫ rubout, but instead prints a space, creating an apparent list of fractions instead.