Clipboard operations in python.
It is very easy to perform copy/paste operations of Clipboard using ctrl+c and ctrl+v , you may think that performing clipboard operations using programming language may be difficult, but we can do this very easily with few lines of code using python. Python have libraries which is only dedicated for clipboard operations. In this short article, we will see three such python libraries.
pyperclip:
pyperclip have methods copy() and paste() to perform copy/paste operation. It is a cross-platform library, which means we can use this library on different OS. Let’s first have a look into the dependencies of pyperclip required in different OS.
On Windows, no additional modules are needed.
On Mac, the pyobjc module is used, falling back to the pbcopy and pbpaste cli
commands. (These commands should come with OS X.).
On Linux, install xclip, xsel, or wl-clipboard (for “wayland” sessions) via package manager.
For example, in Debian:
sudo apt-get install xclip
sudo apt-get install xsel
sudo apt-get install wl-clipboard
Methods to perform copy/paste:
Pyperclip have copy() and paste() methods to perform the operations.
Output:
Pyperclip will convert every data type to string
Other methods of pyperclip:
- determine_clipboard():
Determine the OS/platform and set the copy() and paste() functions
accordingly.
2. waitForNewPaste(timeout=None):
This function call blocks until a new text string exists on the
clipboard that is different from the text that was there when the function
was first called. It returns this text.
This function raises PyperclipTimeoutException if timeout was set to
a number of seconds that has elapsed without non-empty text being put on
the clipboard.
3. waitForPaste(timeout=None):
This function call blocks until a non-empty text string exists on the
clipboard. It returns this text.
This function raises PyperclipTimeoutException if timeout was set to
a number of seconds that has elapsed without non-empty text being put on
the clipboard.
4. set_clipboard(clipboard): Explicitly sets the clipboard mechanism.
pyperclip3
This module is similar to pyperclip, all the methods which is available in pyperclip are also present in this module. The only difference is, it converts every data types to bytes.
Output:
clipboard
This module only have copy() and paste() methods. Other methods which is available in previous libraries is not available in this module.
Conclusion:
We have seen three python modules(pyperclip, pyperclip3, clipboard) which is only dedicated to perform clipboard operations. But, there are packages in Python, which have built-in methods to perform clipboard operation, for instance, to_clipboard of pandas, similarly tkinter, PyQT have their own methods to perform clipboard operations.
Как вставить текст в python
There are several ways to present the output of a program; data can be printed in a human-readable form, or written to a file for future use. This chapter will discuss some of the possibilities.
7.1. Fancier Output Formatting¶
So far we’ve encountered two ways of writing values: expression statements and the print() function. (A third way is using the write() method of file objects; the standard output file can be referenced as sys.stdout . See the Library Reference for more information on this.)
Often you’ll want more control over the formatting of your output than simply printing space-separated values. There are several ways to format output.
To use formatted string literals , begin a string with f or F before the opening quotation mark or triple quotation mark. Inside this string, you can write a Python expression between characters that can refer to variables or literal values.
The str.format() method of strings requires more manual effort. You’ll still use to mark where a variable will be substituted and can provide detailed formatting directives, but you’ll also need to provide the information to be formatted.
Finally, you can do all the string handling yourself by using string slicing and concatenation operations to create any layout you can imagine. The string type has some methods that perform useful operations for padding strings to a given column width.
When you don’t need fancy output but just want a quick display of some variables for debugging purposes, you can convert any value to a string with the repr() or str() functions.
The str() function is meant to return representations of values which are fairly human-readable, while repr() is meant to generate representations which can be read by the interpreter (or will force a SyntaxError if there is no equivalent syntax). For objects which don’t have a particular representation for human consumption, str() will return the same value as repr() . Many values, such as numbers or structures like lists and dictionaries, have the same representation using either function. Strings, in particular, have two distinct representations.
The string module contains a Template class that offers yet another way to substitute values into strings, using placeholders like $x and replacing them with values from a dictionary, but offers much less control of the formatting.
7.1.1. Formatted String Literals¶
Formatted string literals (also called f-strings for short) let you include the value of Python expressions inside a string by prefixing the string with f or F and writing expressions as .
An optional format specifier can follow the expression. This allows greater control over how the value is formatted. The following example rounds pi to three places after the decimal:
Passing an integer after the ‘:’ will cause that field to be a minimum number of characters wide. This is useful for making columns line up.
Other modifiers can be used to convert the value before it is formatted. ‘!a’ applies ascii() , ‘!s’ applies str() , and ‘!r’ applies repr() :
For a reference on these format specifications, see the reference guide for the Format Specification Mini-Language .
7.1.2. The String format() Method¶
Basic usage of the str.format() method looks like this:
The brackets and characters within them (called format fields) are replaced with the objects passed into the str.format() method. A number in the brackets can be used to refer to the position of the object passed into the str.format() method.
If keyword arguments are used in the str.format() method, their values are referred to by using the name of the argument.
Positional and keyword arguments can be arbitrarily combined:
If you have a really long format string that you don’t want to split up, it would be nice if you could reference the variables to be formatted by name instead of by position. This can be done by simply passing the dict and using square brackets ‘[]’ to access the keys.
This could also be done by passing the table as keyword arguments with the ‘**’ notation.
This is particularly useful in combination with the built-in function vars() , which returns a dictionary containing all local variables.
As an example, the following lines produce a tidily-aligned set of columns giving integers and their squares and cubes:
For a complete overview of string formatting with str.format() , see Format String Syntax .
7.1.3. Manual String Formatting¶
Here’s the same table of squares and cubes, formatted manually:
(Note that the one space between each column was added by the way print() works: it always adds spaces between its arguments.)
The str.rjust() method of string objects right-justifies a string in a field of a given width by padding it with spaces on the left. There are similar methods str.ljust() and str.center() . These methods do not write anything, they just return a new string. If the input string is too long, they don’t truncate it, but return it unchanged; this will mess up your column lay-out but that’s usually better than the alternative, which would be lying about a value. (If you really want truncation you can always add a slice operation, as in x.ljust(n)[:n] .)
There is another method, str.zfill() , which pads a numeric string on the left with zeros. It understands about plus and minus signs:
7.1.4. Old string formatting¶
The % operator (modulo) can also be used for string formatting. Given ‘string’ % values , instances of % in string are replaced with zero or more elements of values . This operation is commonly known as string interpolation. For example:
More information can be found in the printf-style String Formatting section.
7.2. Reading and Writing Files¶
open() returns a file object , and is most commonly used with two positional arguments and one keyword argument: open(filename, mode, encoding=None)
The first argument is a string containing the filename. The second argument is another string containing a few characters describing the way in which the file will be used. mode can be ‘r’ when the file will only be read, ‘w’ for only writing (an existing file with the same name will be erased), and ‘a’ opens the file for appending; any data written to the file is automatically added to the end. ‘r+’ opens the file for both reading and writing. The mode argument is optional; ‘r’ will be assumed if it’s omitted.
Normally, files are opened in text mode, that means, you read and write strings from and to the file, which are encoded in a specific encoding. If encoding is not specified, the default is platform dependent (see open() ). Because UTF-8 is the modern de-facto standard, encoding=»utf-8″ is recommended unless you know that you need to use a different encoding. Appending a ‘b’ to the mode opens the file in binary mode. Binary mode data is read and written as bytes objects. You can not specify encoding when opening file in binary mode.
In text mode, the default when reading is to convert platform-specific line endings ( \n on Unix, \r\n on Windows) to just \n . When writing in text mode, the default is to convert occurrences of \n back to platform-specific line endings. This behind-the-scenes modification to file data is fine for text files, but will corrupt binary data like that in JPEG or EXE files. Be very careful to use binary mode when reading and writing such files.
It is good practice to use the with keyword when dealing with file objects. The advantage is that the file is properly closed after its suite finishes, even if an exception is raised at some point. Using with is also much shorter than writing equivalent try — finally blocks:
If you’re not using the with keyword, then you should call f.close() to close the file and immediately free up any system resources used by it.
Calling f.write() without using the with keyword or calling f.close() might result in the arguments of f.write() not being completely written to the disk, even if the program exits successfully.
After a file object is closed, either by a with statement or by calling f.close() , attempts to use the file object will automatically fail.
7.2.1. Methods of File Objects¶
The rest of the examples in this section will assume that a file object called f has already been created.
To read a file’s contents, call f.read(size) , which reads some quantity of data and returns it as a string (in text mode) or bytes object (in binary mode). size is an optional numeric argument. When size is omitted or negative, the entire contents of the file will be read and returned; it’s your problem if the file is twice as large as your machine’s memory. Otherwise, at most size characters (in text mode) or size bytes (in binary mode) are read and returned. If the end of the file has been reached, f.read() will return an empty string ( » ).
f.readline() reads a single line from the file; a newline character ( \n ) is left at the end of the string, and is only omitted on the last line of the file if the file doesn’t end in a newline. This makes the return value unambiguous; if f.readline() returns an empty string, the end of the file has been reached, while a blank line is represented by ‘\n’ , a string containing only a single newline.
For reading lines from a file, you can loop over the file object. This is memory efficient, fast, and leads to simple code:
If you want to read all the lines of a file in a list you can also use list(f) or f.readlines() .
f.write(string) writes the contents of string to the file, returning the number of characters written.
Other types of objects need to be converted – either to a string (in text mode) or a bytes object (in binary mode) – before writing them:
f.tell() returns an integer giving the file object’s current position in the file represented as number of bytes from the beginning of the file when in binary mode and an opaque number when in text mode.
To change the file object’s position, use f.seek(offset, whence) . The position is computed from adding offset to a reference point; the reference point is selected by the whence argument. A whence value of 0 measures from the beginning of the file, 1 uses the current file position, and 2 uses the end of the file as the reference point. whence can be omitted and defaults to 0, using the beginning of the file as the reference point.
In text files (those opened without a b in the mode string), only seeks relative to the beginning of the file are allowed (the exception being seeking to the very file end with seek(0, 2) ) and the only valid offset values are those returned from the f.tell() , or zero. Any other offset value produces undefined behaviour.
File objects have some additional methods, such as isatty() and truncate() which are less frequently used; consult the Library Reference for a complete guide to file objects.
7.2.2. Saving structured data with json ¶
Strings can easily be written to and read from a file. Numbers take a bit more effort, since the read() method only returns strings, which will have to be passed to a function like int() , which takes a string like ‘123’ and returns its numeric value 123. When you want to save more complex data types like nested lists and dictionaries, parsing and serializing by hand becomes complicated.
Rather than having users constantly writing and debugging code to save complicated data types to files, Python allows you to use the popular data interchange format called JSON (JavaScript Object Notation). The standard module called json can take Python data hierarchies, and convert them to string representations; this process is called serializing. Reconstructing the data from the string representation is called deserializing. Between serializing and deserializing, the string representing the object may have been stored in a file or data, or sent over a network connection to some distant machine.
The JSON format is commonly used by modern applications to allow for data exchange. Many programmers are already familiar with it, which makes it a good choice for interoperability.
If you have an object x , you can view its JSON string representation with a simple line of code:
Another variant of the dumps() function, called dump() , simply serializes the object to a text file . So if f is a text file object opened for writing, we can do this:
To decode the object again, if f is a binary file or text file object which has been opened for reading:
JSON files must be encoded in UTF-8. Use encoding=»utf-8″ when opening JSON file as a text file for both of reading and writing.
This simple serialization technique can handle lists and dictionaries, but serializing arbitrary class instances in JSON requires a bit of extra effort. The reference for the json module contains an explanation of this.
pickle — the pickle module
Contrary to JSON , pickle is a protocol which allows the serialization of arbitrarily complex Python objects. As such, it is specific to Python and cannot be used to communicate with applications written in other languages. It is also insecure by default: deserializing pickle data coming from an untrusted source can execute arbitrary code, if the data was crafted by a skilled attacker.
Как записать строку в текстовый файл или добавить текст на Python
В следующем примере у нас есть существующий файл data.txt с некоторым текстом. Мы добавим еще немного текста к существующим данным, выполнив шаги, указанные выше.
Введите текстовый файл – data.txt перед запуском примера в Python.
Текстовый файл с добавленным текстом после запуска примера в Python.
Пример 2: добавление в текстовом режиме
Вы можете обрабатывать файл в текстовом или двоичном режиме. По умолчанию файл будет обрабатываться в текстовом режиме. В следующем примере мы будем обрабатывать файл в текстовом режиме, добавляя «t» к режиму добавления «a».
В этом руководстве мы узнали, как добавить текст в файл на Python с помощью примеров программ.
Теперь вы можете сохранить или записать строку в текст файла в постоянном хранилище данных с помощью Python.
- Открыть файл в режиме записи с помощью функции open().
- Записать строку в файл с помощью метода write().
- Закрыть файл с помощью метода close().
Пример 1
В следующем примере мы возьмем строковую константу и запишем строку в текстовый файл, выполнив указанную выше последовательность шагов.
Метод write() возвращает количество символов, записанных в текстовый файл.
Обратите внимание, что этот вид записи в текстовый файл перезаписывает данные, если файл уже существует. Если файла нет, он создает новый файл, а затем записывает строку в файл.
Пример 2: запись в текстовом режиме
Файл можно открыть в двух режимах: первый – текстовый, второй – двоичный. По умолчанию файл открывается в текстовом режиме. Однако вы можете сами указать режим.
В следующем примере мы откроем файл в текстовом режиме, добавив «t» к режиму, и запишем строку в текстовый файл, выполнив последовательность шагов, упомянутую в начале этого руководства.
Запись в текстовый файл, кроме строки
Если вы хотите записать в файл какой-либо объект в Python, кроме строки или объекта bytes, с помощью метода write(), вы должны сначала преобразовать их в объект строки или bytes.
Заключение
В этом руководстве мы узнали, как записать строку в текстовый файл с помощью примеров программ.
How do I copy a string to the clipboard?
I’m trying to make a basic Windows application that builds a string out of user input and then adds it to the clipboard. How do I copy a string to the clipboard using Python?
28 Answers 28
Actually, pywin32 and ctypes seem to be an overkill for this simple task. tkinter is a cross-platform GUI framework, which ships with Python by default and has clipboard accessing methods along with other cool stuff.
If all you need is to put some text to system clipboard, this will do it:
And that’s all, no need to mess around with platform-specific third-party libraries.
If you are using Python 2, replace tkinter with Tkinter .
I didn’t have a solution, just a workaround.
Windows Vista onwards has an inbuilt command called clip that takes the output of a command from command line and puts it into the clipboard. For example, ipconfig | clip .
So I made a function with the os module which takes a string and adds it to the clipboard using the inbuilt Windows solution.
As previously noted in the comments however, one downside to this approach is that the echo command automatically adds a newline to the end of your text. To avoid this you can use a modified version of the command:
You can use pyperclip — cross-platform clipboard module. Or Xerox — similar module, except requires the win32 Python module to work on Windows.
The simplest way is with pyperclip. Works in python 2 and 3.
To install this library, use:
If you want to get the contents of the clipboard:
You can use the excellent pandas, which has a built in clipboard support, but you need to pass through a DataFrame.
You can also use ctypes to tap into the Windows API and avoid the massive pywin32 package. This is what I use (excuse the poor style, but the idea is there):
Here’s the most easy and reliable way I found if you’re okay depending on Pandas. However I don’t think this is officially part of the Pandas API so it may break with future updates. It works as of 0.25.3
For some reason I’ve never been able to get the Tk solution to work for me. kapace’s solution is much more workable, but the formatting is contrary to my style and it doesn’t work with Unicode. Here’s a modified version.
The above has changed since this answer was first created, to better cope with extended Unicode characters and Python 3. It has been tested in both Python 2.7 and 3.5, and works even with emoji such as \U0001f601 (��) .
Update 2021-10-26: This was working great for me in Windows 7 and Python 3.8. Then I got a new computer with Windows 10 and Python 3.10, and it failed for me the same way as indicated in the comments. This post gave me the answer. The functions from ctypes don’t have argument and return types properly specified, and the defaults don’t work consistently with 64-bit values. I’ve modified the above code to include that missing information.