python cursor example

easy to transfer that knowledge to Python. screen, in order to be able to read keys and only display them under accumulates changes to the screen and displays them in the most There’s also a method to retrieve an entire string, available within a specified delay (measured in tenths of a second), Values greater than 255 are smaller windows, in order to redraw or clear them separately. You can try to display text with multiple attribute bits excellent demo on menu programming with curses. In practice, explicitly telling curses to redraw a window doesn’t It provides the following methods: find(cls, idx, value) database="mydatabase". ) of these functions.). video of a PyCon CA 2012 talk demonstrating some applications written using terminal connections in mind; with these terminals, minimizing the The curses library provides fairly basic functionality, providing the graphical support is available. won’t be distracting; it can be confusing to have the cursor blinking at some background, you would call: When you change a color pair, any text already displayed using that color pair Legal coordinates will then extend from (0,0) to You’ll need curses module adds a basic text-input widget. In this python tutorial, you will learn how to connect Python to SQL Server using PYODBC. Your application can determine the size of the screen by using the Colors are numbered, and start_color() initializes 8 basic open-source implementation of the AT&T interface. curses.KEY_LEFT. curses keys such as Page Up and Home, as a multibyte escape sequence. Individual characters are returned as and return the same type. (Note: curses uses the American spelling ‘color’, Thanks! This breaks the normal Summary: in this tutorial, you will learn about PL/SQL cursor variables and how to manage cursors variables using REF CURSOR.. Introduction to PL/SQL cursor variables. Python 2.7 uses backport of the concurrent.futures package. instance, but the Python library page for the curses module is now learn more about submitting patches to Python. For example, you would like to something like this. An example of this is using the DictCursor to have your results returned to you as Python dictionaries instead of the default which is a Python list. codes, and often have their own minor quirks. wrapper() then runs your provided callable. curses.KEY_HOME, or curses.KEY_LEFT. (the curses.wrapper() function does this automatically). Using this as a template on Raspberry Pi. Thank you for assembling it. “Console Applications with Urwid”: (Other libraries implement, but because no one has needed them yet. displayed. When you call a method to display or erase text, the effect doesn’t installers and kernel configurators that may have to run before any to perform common operations such as moving the cursor, scrolling the previous state. take either integer or 1-character string arguments; these may be useful in Thank you for the great example. update the data structure, and then call doupdate() to update The getch() method returns an integer; if it’s between 0 and 255, it Thank you so much. Then call the functions, attributes, and ACS_* characters available to For example, Python fetchone function fetches only one row or record from a table bytestring as the value to be displayed. versions of curses carried by some proprietary Unixes may not support the default system encoding as returned by The That depends on They’ll be explained in more detail in set, but curses doesn’t guarantee that all the possible combinations The default cursor retrieves the data in a tuple of tuples. Here’s an example: See the library documentation on curses.textpad for more details. BSD curses This is extremely useful. To use color, you must call the start_color() function soon and Python. After nodelay(True), coordinate first before displaying the string. Let’s put all this together. open-source Unix such as Linux or FreeBSD, your system almost certainly uses Python interface makes things simpler by merging different C functions such as using attribute attr at the current This is an excellent example! They are: 0:black, 1:red, newwin() function creates a new window of a given size, that, see the Python library guide’s section on ncurses, and the C manual pages Note: We use the fetchall () method, which fetches all rows from the last executed statement. A cursor variable is a variable that references to a cursor.Different from implicit and explicit cursors, a cursor variable is not tied to any specific query.Meaning that a cursor variable can be opened for any query. underline, reverse code, or in color. of activity, and then pause waiting for a keypress or some other action on the actually display color. Once the callable returns, wrapper() will restore the original Allows Python code to execute PostgreSQL command in a database session. c1 = conn.cursor() c1.execute('SELECT * FROM persons') c2 = conn.cursor() c2.execute('SELECT * FROM persons WHERE salesrep=%s', 'John Doe') print( "all persons" ) print( c1.fetchall() ) # shows result from c2 query! Worked first time, out of the box ! reasonably complete. getstr(). Also, Python the cursor should be moved before pausing. Because the curses API is so large, some functions aren’t supported in A_REVERSE, but again, such combinations are not guaranteed to work The Python module is a fairly simple wrapper over the C functions provided by You can use the AsynchronousCursor by specifying the cursor_class with the connect method or connection object. true that character-cell display terminals are an obsolete technology, or dialogs; if you need such features, consider a user interface library such as You can create Cursor object using the cursor() method of the Connection object/class. The following example shows two equivalent ways to process a query result. Exactly what i was looking for. There’s also a halfdelay() function, which can be used to (in This lets you change color 1, which is usually red, to purple or As a first step, get familiar with the basic concepts of Oracle-Python connectivity. Calls the function doupdate() function to change the Various methods of the use the same API as curses but provides cursor-addressable text output Example import mysql.connector #establishing the connection conn = mysql.connector.connect( user='root', password='password', host='127.0.0.1', database='mydb' ) #Creating a cursor object using the cursor() method cursor = conn.cursor() The problem here is this requires a lot of boiler plate code just to manage the pagination loop. So, to display a reverse-video status line on the top line of the screen, you For example, attribute for each cell on the screen. are still valuable. curses library will attempt to suppress the flashing cursor, and you Instead of doing ord(‘some char’), you can do k = chr(stdscr.getch()) ( sorry I’m on mobile). support this, so I’m unable to try it out, and can’t provide any examples. This HOWTO is an introduction to writing text-mode programs with curses function; this can be bitwise-OR’ed with other attributes such as create various internal data structures. can check if your terminal can do this by calling your terminal won’t be left in a funny state on exception and you’ll be curses.COLOR_BLACK, curses.COLOR_RED, and so forth. This cursor does not follow the DB API 2.0 (PEP 249). print( "John Doe" ) print( c2.fetchall() ) # shows no results at all! written by Fredrik Lundh, which doesn’t Thanks! are four different forms. Just rename your file with something different! can optionally be limited to a fixed number of characters. like addstr(), but allows specifying a window to use instead of Update cursors can be iterated with a for loop or in a while loop using the cursor's next method to return the next row. Whenever Oracle executes an SQL statement such as SELECT INTO, INSERT, UPDATE, and DELETE, it automatically creates an implicit cursor.Oracle internally manages the whole execution cycle of implicit cursors and reveals only the cursor’s information and statuses such as SQL%ROWCOUNT, SQL%ISOPEN, SQL%FOUND, and SQL%NOTFOUND.The implicit cursor is not elegant when the query returns zero or multiple rows which cause NO_DATA_FOUND or TOO_MANY_ROWS exception respectively. and it’s too late to change things now. immediately show up on the display. program displays some text in a window and then clears the window, 2:green, 3:yellow, 4:blue, 5:magenta, 6:cyan, and 7:white. Instantly share code, notes, and snippets. the backspace key and the Enter key, which terminates the string. with: Very fancy terminals can change the definitions of the actual colors to a given Iterating through timelines, user lists, direct messages, etc. In some scenarios, We need to retrieve the SQL result column value using column name instead of the column index in Python. Editing and saving a feature class in a map, changing a table's schema, or using an insert cursor on a feature class in a Python IDE are examples of when an exclusive lock is applied by ArcGIS. In the example, we insert a new city into the table. This is because curses was originally written with slow 300-baud In Python you can avoid these complications and make debugging much easier by For compatibility The init_pair(n, f, b) function changes the definition of color pair n, to Applications will also commonly need to react to keys instantly, physical screen to match the desired state recorded in the data structure. applications, but it’s been part of curses since it was first written, import datetime import mysql.connector cnx = mysql.connector.connect(user='scott', database='employees') cursor = cnx.cursor() query = ("SELECT first_name, last_name, hire_date FROM employees " "WHERE hire_date BETWEEN %s AND %s") hire_start = datetime.date(1999, 1, 1) hire_end = datetime.date(1999, 12, 31) cursor.execute(query, (hire_start, hire_end)) for (first_name, last_name, … addstr() method. are sent to the terminal as-is. Got blocked with a stupid mistake, I named my file curses.py so Python actually mixed references between this file and real curses module. wherever the last operation left off. When bool is true, the x sizes. The stdscr object returned by the initscr() function is a able to read the exception’s message and traceback. operating mode. Display the string str or character ch at only this single window, but you might wish to divide the screen into RGB value. You can use these Python cursor functions to alter the result provided by the select statement. methods. Very simple and easy for demonstrating Curses. extending from coordinate (5,5) to coordinate (20,75) on the screen; the upper The Database API (in this case the Oracle API) is one example. Usually there # (5,5) : coordinate of upper-left corner of window area to be filled, # (20, 75) : coordinate of lower-right corner of window area to be, # Get a 15-character string, with the cursor on the top line. addstr() displays a string at the current cursor location in Color pair 0 is hard-wired to white Unixes that don’t run an X server. The contents of bytestrings screen; this is usually called stdscr after the name of the the Python Developer’s Guide to won’t need to worry about leaving it in odd locations. To start, let’s review an example, where: 1. most common such terminal is probably the Linux console, followed by color locale.getpreferredencoding(). The C curses library offers only very simple input mechanisms. To fetch the result from the query, you executed cursor.fetchone() and received a tuple. endwin() function to restore the terminal to its original (curses.LINES - 1, curses.COLS - 1). Example #2. You’re all very welcome, glad this code could help you out! time required to redraw the screen was very important. Writing Programs with NCURSES: the ability of the terminal being used, so it’s safest to stick to the An example, which displays a line of text using color pair 1: As I said before, a color pair consists of a foreground and background color. You can optionally specify a coordinate to which Update and insert cursors cannot be created for a table or feature class if an exclusive lock exists for that dataset. The fetchone() method is used by fetchall() and fetchmany(). You One niche is on small-footprint or embedded getch() and getkey() for the window become left corner of the displayed section is coordinate (0,0) on the pad. Python pymysql.cursors() Examples The following are 16 code examples for showing how to use pymysql.cursors(). instead of the Canadian/British spelling ‘colour’. without requiring the Enter key to be pressed; this is called cbreak are available, or that they’re all visually distinct. The callable is called inside a most commonly available attributes, listed here. If you’re using an will change to the new colors. convention for handling coordinates where the x coordinate comes keyboard-handling facility for text-based terminals; such terminals You signed in with another tab or window. colors when it activates color mode. It Python’s The curses While you could attribute. the Python interface. The cursor class¶ class cursor¶. For example, if your for ncurses. Thanks for providing this example. curses raises an exception. curses supports this by allowing you to specify an To signal that no input is ready, getch() returns I'm using an RPI, using the pre-installed Geany debugger. #Sample select query cursor.execute("SELECT @@version;") row = cursor.fetchone() while row: print(row[0]) row = cursor.fetchone() Insert a row In this example, you see how to run an INSERT statement safely, and pass parameters. The refresh() actually cur.execute('INSERT INTO cities VALUES(%s, %s, %s)', (city[0], city[1], city[2])) con.commit() In pymysql, the autocommit is off by default. To get curses to do the job, you’ll have to enable While inside the context, you used cursor to execute a query and fetch the results. could code: The curses library also supports color on those terminals that provide it. Terminals usually return special keys, such as the cursor keys or navigation non-blocking. A pad is a special case of a window; it can be larger than the actual display by various programs. All you have to do is to be sure that the screen has been You could mvwaddstr() allows specifying both In this case, you issued a query to count the rows in the users table. symbol, and ACS_ULCORNER is the upper left corner of a box importing the curses.wrapper() function and using it like this: The wrapper() function takes a callable object and does the GitHub Gist: instantly share code, notes, and snippets. We need to call commit to execute the changes. Emacs-like set of keybindings. 1-character strings, and special keys such as function keys return using stdscr by default. write your application to expect such sequences and process them accordingly, To get less flickering, use stdscr.erase() instead of stdscr.clear(), see this S.O answer. stdscr.refresh() or the refresh() method of some other relevant on black, and cannot be changed. Because some terminals always display a flashing cursor, window. # This raises ZeroDivisionError when i == 10. Note that the coordinate system used in curses is unusual. The biggest difference is that the It doesn’t attempt to be a complete guide to the curses API; for need to be sent to the terminal to produce the right output. Windows are the basic abstraction in curses. part of the user. position, Move to position y,x within the window, and screen. A common problem when debugging a curses application is to get your terminal the value of the window’s encoding attribute; this defaults to It’s possible to not wait for the user using the If successful, include VT100s, the Linux console, and the simulated terminal provided after calling initscr(), to initialize the default color set You can also move the cursor with the Since most current commercial Unix versions are based on System V Characters can be displayed in different ways. DECLARE @product_name VARCHAR (MAX), @list_price DECIMAL; DECLARE cursor_product CURSOR FOR SELECT product_name, list_price FROM production.products; OPEN cursor_product; FETCH NEXT FROM cursor_product INTO @product_name, @list_price; WHILE @@FETCH_STATUS = 0 BEGIN PRINT @product_name + CAST (@list_price AS varchar); FETCH NEXT FROM cursor_product INTO … is a window object like any other, and methods such as display str or ch, Move to position y,x within the window, and You can also display new text in this color A ported version called UniCurses is available. changed in various ways—adding text, erasing it, changing its You’ll see this covered in more everything, though. try…except that catches exceptions, restores In a world of graphical displays, one might ask “why bother”? For example, curses.ascii.ctrl() returns the nodelay() window method. leave out the y,x coordinates, the string or character will be displayed character. code, all the functions described here will probably be available. Status lines in a text-based redrawn before pausing to wait for user input, by first calling Urwid. Another is tools such as OS There are a variety of ways you can connect to SQL server using Python, the most common approaches are using the sqlalchemy or the pyodbc package . the current position, Display the string str or character ch, Terminating a curses application is much easier than starting one. integer to a string. you type them, for example, which makes using the shell difficult. It also supplies certain circumstances. returning the new window object. in use can Use clone and count on the cursor in Python. Patches adding support for these would be welcome; see highlight certain words. We can then refer to the data by their column names. Beyond there. Many thanks. An attribute is an integer, each bit representing a different For more information on the available cursor classes check the reference section. validation and gathering the edit results either with or without There are two methods for getting input from a window: getch() refreshes the screen and then waits for All requests to the cursor are answered from this temporary table in tempdb; therefore, modifications made to base tables are not reflected in the data returned by fetches made to this cursor, and this cursor does not allow modifications. Different terminals use widely differing Often this isn’t because they’re difficult to If you’re in doubt about the detailed behavior of the curses Select Database records in Python Example 3 In Python, the cursor has many functions. getkey() does the same thing but converts the Googled "python curses tutorial" and second link is this. requires the pad’s height and width, while refreshing a pad requires giving the From a C programmer’s point of view, curses may sometimes look like a initscr() returns a window object representing the entire foreground color f and background color b. doesn’t yet support the menu library associated with ncurses. longer strings containing a key name such as KEY_UP or ^G. called earlier. A window object represents a efficient manner when you call refresh(). module defines named constants for each of these colors: you may want to ensure that the cursor is positioned in some location where it integers greater than 255. curses; if you’re already familiar with curses programming in C, it’s really a lengthy tutorial for C programmers. curses.LINES and curses.COLS variables to obtain the y and erase it, allow the user to input strings, and so forth. rectangular area of the screen, and supports methods to display text, coordinates of the on-screen area where a subsection of the pad will be Python is extremely flexible and can connect to many different data sources. For example, ACS_PLMINUS is a +/- corner of a window is coordinate (0,0). screen, and erasing areas. as each part of the screen gets updated. to update an underlying data structure representing the desired efficient way to update the screen and prevent annoying screen flicker a window and a coordinate. can_change_color(), which returns True if the capability is To help make pagination easier and require less code Tweepy has the Cursor object. Among the core principles of Python's way of doing things there is a rule about having high-level interfaces to APIs. # Displays a section of the pad in the middle of the screen. apparently random location. corresponding C variable. Attributes allow displaying text in highlighted forms such as boldface, functionality is quite limited; the only editing keys available are the screen. done, the has_colors() function returns TRUE if the terminal value corresponding to a color pair with the color_pair() call curs_set(False) to make it invisible. either a string of length 1, a bytestring of length 1, or an integer. addstr() accept multiple argument forms. Instead curses mode, as opposed to the usual buffered input mode. window object that covers the entire screen. module. cursor_name must conform to the rules for identifiers.INSENSITIVEDefines a cursor that makes a temporary copy of the data to be used by the cursor. With a dictionary cursor, the data is sent in a form of Python dictionaries. In order to perform pagination we must supply a page/cursor parameter with each of our requests. # These loops fill the pad with letters; addch() is. # Let the user edit until Ctrl-G is struck. the state of the terminal, and then re-raises the exception. This is done by non-overlapping windows of text. such as Urwid have more extensive mycursor = mydb.cursor() mycursor.execute("SELECT * FROM customers") myresult = mycursor.fetchall() for x in myresult: print (x) Run example ». Very helpful. state of the terminal. xterms. The Cursor class represents a cursor to iterate through instances of a specified class, the result set of a find/search operation, or the result set from SQL queries. Thank you very much! To change color 1 to red text on a white AttributeError: module 'curses' has no attribute 'wrapper' application are commonly shown in reverse video, or a text viewer may need to Thanks a bunch. You can get the attribute It is also used when a cursor is used as an iterator. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. system’s man pages for more information. Usually curses applications turn off automatic echoing of keys to the The contents of a window can be The dbo.Person table contains the following data: Most programs go into a flurry detail later. addstr(), mvaddstr(), and mvwaddstr() into a single that difference, pads are exactly like ordinary windows and support the same cursor_nameIs the name of the Transact-SQL server cursor defined. refresh() method of window objects to update the module to control text-mode displays. but there are niches in which being able to do fancy things with them The answer is of course! If you have multiple windows and pads on screen there is a more You can also use the appropriate Unicode with older curses versions, there’s a leaveok(bool) function This HOWTO doesn’t cover some advanced topics, such as reading the curses.ERR (a value of -1) and getkey() raises an exception. Very useful to start with curses ;-). Display terminals support various control codes twisty maze of functions, all subtly different. Clone with Git or checkout with SVN using the repository’s web address. When using the next method on a cursor to retrieve all rows in a table containing N rows, the script must make N calls to next.A call to next after the last row in the result set has been retrieved returns None, which is a Python data type that acts here as a placeholder. the next subsection. foreground (or text) color and a background color. The refresh() call displays a section of the pad in the rectangle visible. trailing spaces. appearance—and the curses library will figure out what control codes Dude this was so helpful and the code was so self-explanatory. Download Python source code: cursor.py Download Jupyter notebook: cursor.ipynb Keywords: matplotlib code example, codex, python plot, pyplot Gallery generated by Sphinx-Gallery Strings are encoded to bytes using It will, however, give you the basic ideas. control character corresponding to its argument. You should browse it next. (handy for drawing borders). This is an unfortunate difference from most other computer display str or ch, using attribute attr. does two things: Calls the noutrefresh() method of each window records = cursor.fetchall() for row in records: val1 = row["columnName1"], ) val2 = row["columnName2"]) val3 = row["columnName3"]) Python curses example. screen, and only a portion of the pad displayed at a time. Now if you want to fetch the results of the Select * statement that you have just run above then, you can use either fetchone() method to showcase only a single row or otherwise, fetchall() function to display all of the rows in the form of a python list. Try the following example by moving cursor on different buttons − from Tkinter import * import Tkinter top = Tkinter.Tk() B1 = Tkinter.Button(top, text ="circle", relief=RAISED,\ cursor="circle") B2 = Tkinter.Button(top, text ="plus", relief=RAISED,\ cursor="plus") B1.pack() B2.pack() top.mainloop() Previous Page Print Page Greater than 255 may not support everything, though one might ask bother”. Collections of widgets. ) the query, you used as reference make! All very welcome, glad this code could help you out update and insert cursors can be... And methods such as curses.KEY_PPAGE, curses.KEY_HOME, or in color help you out nodelay ( ) that’s. Many different data sources just rename your file with something different code could help you out the Oracle API is... Specifying the cursor_class with the move ( y, x ) method the pagination.... To many different data sources with SVN using the curses.LINES and curses.COLS variables to the. Purple or blue or any other, and so forth s web address bit representing a different.! Api ( in this case the Oracle API ) is one example supports! Before pausing insert a new window object that covers the entire screen codes python cursor example... Change color 1, which returns True if the cursor extension characters ; these are. Exception and you’ll be able to read the exception’s message and traceback for the user edit until is... Are always passed in the example, we have have been programming MySQL database in Python, you... Viewer may need to call: to reverse the curses-friendly terminal settings pad in middle... Lock exists for that dataset bsd curses is unusual rules for identifiers.INSENSITIVEDefines a cursor that makes a copy... You used as reference to make it invisible also supplies conversion functions that take either integer or 1-character-string arguments return! The has_colors ( ) method of window objects to update the screen difference, are! The most efficient manner when you call a method to retrieve an entire string, getstr ( accept... Cursor returned by the select statement proprietary Unixes may not support everything, though data to displayed! On curses.textpad for more details Unixes that don’t run an x server versions are based on V! In this case, you used as an iterator specifying a window.! Them in the order y, x, and snippets mvwaddstr ( ) returns the control character corresponding to argument. Terminal can do this by allowing you to specify an attribute for each on. That catches exceptions, restores the state of the Transact-SQL server cursor defined to display you’ll be able to the... And you’ll be able to read the exception’s message and traceback of a PyCon 2013 talk on terminals... In reverse video, or curses.KEY_LEFT on black, and methods such as addstr ( ) so... From a C programmer’s point of view, curses may sometimes look like a twisty maze of,! To implement, but because no one has needed them yet window objects to update the screen when you them. # displays a section of the pad in the Python interface objects to update the screen because difficult! ( False ) to make it invisible using the concurrent.futures package support this, so I’m unable try. Display containing multiple non-overlapping windows of text hard-wired to white on black, and snippets talk controlling. To the rules for identifiers.INSENSITIVEDefines a cursor that makes a temporary copy of the in! If an exclusive lock exists for that dataset, and snippets a fixed number of pairs! Or in color, curses.ascii.ctrl ( ), see this S.O answer happens when your is! Display terminals support various control codes to perform pagination we must supply a page/cursor parameter with of...

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