I'm trying to lean sqlite3 and create databases, but I'm having trouble getting started. I go to the Terminal and start things off by typing sqlite3. I get the following prompt:
sqlite>
I installed sqlAcademy and am trying to work through the tutorial, but with examples like:
>>> import sqlalchemy
>>> sqlalchemy.__version__
0.7.0
They appear to be typing in the Terminal, but my code shows an error:
sqlite> import sqlalchemy;
Error: near "import": syntax error
Is there a wrapper I should be using in Terminal so I can type in Python? Do I need to individually write, compile, and run all of the example or is there an easier way?
I know this sounds vague, but I think I'm doing something very obvious wrong. Just too new to know what it is.
That's because you're running in sqlite terminal. The sample code should be run from python's terminal.
To further expand on Demian's answer:
In the terminal type:
$ python
you will get (or similar depending on which version of python you have installed)
Python 2.7.1+ (r271:86832, Apr 11 2011, 18:13:53)
[GCC 4.5.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>
From there you can enter your import sqlalchemy
Alternatively you can create a python script file (*.py) and put your code in it. Then run run the code by changing to the directory that your files are in, and entering
python filename.py
Hope that helps.
Related
I am trying to use a code which was written for python 2 and may run with python 3.6.0, but it does not run with python 3.6.4. It imports the IN module, and uses IN.IP_RECVERR. I tried to google it, but it is a 'bit' hard to find anything about a module called IN (naming fail?). To demonstrate in REPL, that it works in python 2, but not in 3.6.4:
$ python2
Python 2.7.14 (default, Jan 5 2018, 10:41:29)
[GCC 7.2.1 20171224] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import IN
>>> IN.IP_RECVERR
11
>>>
$ python3
Python 3.6.4 (default, Jan 5 2018, 02:35:40)
[GCC 7.2.1 20171224] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import IN
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'IN'
>>>
What is the replacement for this IN module in newer versions of python 3?
This is presumably the private plat-linux/IN.py module, which was never intended to be used. There have been plans to remove these plat-* files for a few zillion years, but it looks like it finally happened in issue 28027 for 3.6. As mentioned in What's New in Python 3.6:
The undocumented IN, CDROM, DLFCN, TYPES, CDIO, and STROPTS modules have been removed. They had been available in the platform specific Lib/plat-*/ directories, but were chronically out of date, inconsistently available across platforms, and unmaintained. The script that created these modules is still available in the source distribution at Tools/scripts/h2py.py.
Most of the useful constants that are at least somewhat portable (as in you can expect them to be available and work the same on your old laptop's linux and your brand-new Galaxy's linux, if not on OS X or Solaris) have long been made available through other places in the stdlib.
I think this specific one you're looking for is an example of not completely useless, but not portable enough to put anywhere safe, because linux documents the existence of IP_RECVERR, but not its value. So, you really need the version from your own system's ip headers.
The way to do this safely, if you actually need the IN module, is to run Tools/scripts/h2py.py with the Python version you're using, on the specific platform you need. That will generate an IN.py from the appropriate headers on your system (or on your cross-compilation target), which you can then use on that system. If you want to distribute your code, you'd probably need to put a step to do that into the setup.py, so it'll be run at install time (and at wheel-building time for people who install pre-built wheels, but you may need to be careful to make sure the targets are specific enough).
If you don't need to be particularly portable, you just need to access the one value in a few scripts that you're only deploying on your laptop or your company's set of identical containers or the like, you may be better off hardcoding the values (with a nice scare comment explaining the details).
In Python 2.7, how can I make the IDLE app use \__future__ division without typing from \__future__ import division manually every time I start IDLE?
If I put from \__future__ import division at the top of my .idlestartup file it is ignored, even though the other things in .idlestartup get executed. For example:
~> cat >.idlestartup
from __future__ import division
print("Executing .idlestartup")
~> idle -s
Here's what my IDLE window looks like after I try dividing:
Python 2.7.8 |Anaconda 2.1.0 (x86_64)| (default, Aug 21 2014, 15:21:46)
[GCC 4.2.1 (Apple Inc. build 5577)] on darwin
Type "copyright", "credits" or "license()" for more information.
>>>
Executing .idlestartup
>>> 2/3
0
>>>
I am using Mac OS X 10.9.5 Mavericks (also had the same problem on earlier versions of OS X). Note that the command line version above was included to make it easier to show what I'm talking about, but the version I'm more interested in is running the IDLE app from the GUI.
The solution suggested by Ashwini Chaudhary below worked for running the Anaconda version from the command line but not for running the IDLE app.
I was finally able to get future division working automatically in the IDLE app by adding "sys.argv.insert(1, '-Qnew')" to /Applications/IDLE.app/Contents/MacOS/IDLE. Both that and Ashwini Chaudhary's solution below seem brittle. I wonder if there is a cleaner way.
Adding the __future__ statement at the top of /usr/lib/python2.7/idlelib/PyShell.py did the job for me.
I am on Ubuntu, the path may vary for other OS:
>>> import idlelib
>>> idlelib.PyShell.__file__
'/usr/lib/python2.7/idlelib/PyShell.py'
I use Windows 7, 64bit, with installed Python 2.7 and Oracle instant client 10.2.0.3.
I try to set up connection with Oracle database from python. In order to do this, I download cx_Oracle-5.1.2-10g.win32-py2.7.msi and install it.
upd. it's an error. i meant cx_Oracle-5.1.2-10g.win-amd64-py2.7.msi
Then I try to connect use code like this
import cx_Oracle
ad = cx_Oracle.makedsn('127.0.0.1', '1521', 'XE')
con = cx_Oracle.connect('user', 'password', ad)
And check that connection is set up correctly by selecting some rows from database table.
And at this moment happens something interesting.
I perform described actions in three different environments: Sublime Text 3, Python Console and ipython.
The problem is in ST3 and in ipython this chunk of code silently crashes on line with cx_Oracle.connect (I checked that with print statement in different places).
But in python console and idle it works just fine. Moreover sometimes it works properly in ipython, but I cannot understand why and when. In ST3 it never works.
ST shows message [Finished in 0.4s with exit code 3221226356]
To demonstrate behavior in python and ipython console I attach copypaste of simple case from cmd. It just exits from ipython.
C:\Users\Alexey>python
Python 2.7.7 (default, Jun 1 2014, 14:21:57) [MSC v.1500 64 bit (AMD64)] on win
32
Type "help", "copyright", "credits" or "license" for more information.
>>> import cx_Oracle
>>> cx_Oracle.connect()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
cx_Oracle.DatabaseError: ORA-12560: TNS:protocol adapter error
>>> exit()
C:\Users\Alexey>ipython
Python 2.7.7 (default, Jun 1 2014, 14:21:57) [MSC v.1500 64 bit (AMD64)]
Type "copyright", "credits" or "license" for more information.
IPython 2.2.0 -- An enhanced Interactive Python.
? -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help -> Python's own help system.
object? -> Details about 'object', use 'object??' for extra details.
In [1]: import cx_Oracle
In [2]: cx_Oracle.connect()
C:\Users\Alexey>
Where is the problem? How can I solve it?
Thanks in advance.
PS. I tried to handle exception in ST3 and ipython such as
try:
cx_Oracle.connect()
except Exception as e:
print e
but script terminates on cx_Oracle.connect() and no message appears.
I tried this environment myself and did not experience the same behavior. Perhaps use faulthandler or gdb or some equivalent to figure out where the crash is taking place? cx_Oracle is still maintained (by me) so if you can find a bug I'll happily fix it! It may also be a problem with IPython or ST3 or in some interaction between these two and cx_Oracle. Since I can't replicate the problem, however, you'll need to provide a stack trace of some sort so we can proceed further.
I have weird problem that I cannot put my finger on. There is a program that I use (and contribute from time to time) that has colorized console output. Everything worked great until I reinstalled Windows. Now I cannot get colorized output.
This is the script that is used for colorizing.
I have managed to narrow down the problem to, more or less, simple situation, but I have no idea what is wrong.
This is console prompt that works as expected (string test is printed in red):
Python 2.7.3 (default, Apr 10 2012, 23:24:47) [MSC v.1500 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.path.insert(0, r'c:\bin\SV\tea\src')
>>> from tea.console.color import cprint, Color
>>> cprint('test\n', Color.red)
test
>>>
But when I run following script with same version of python I get output test but not in red color (there is no color, just default console color):
import sys
sys.path.insert(0, r'c:\bin\SV\tea\src')
from tea.console.color import cprint, Color
cprint('test\n', Color.red)
The same setup worked before I reinstalled my system.
I have checked, environment variables in interactive mode and script are the same.
I have tried this in standard windows command prompt and Console, program that I
usually use.
OS in question is Windows 8 and before reinstall this was also used on Windows 8.
Same code with same setup works at computer at work (Windows 7).
I have Python 2.7 and Python 3.3 installed (as I did before). I have tried to run script
with calling python interpreter directly (c:\Python27\python.exe) or with py -2,
but it does not help.
IPython and mercurial colorizes output as it should.
Any ideas what can I try to make this work?
Edit:
Maybe it was not clear, but script I use to colorize output is given in a link in question. Here it is once again:
https://bitbucket.org/alefnula/tea/src/dc14009a19d66f92463549332a321b29c71d47b8/src/tea/console/color.py?at=default
I have found the problem and solution.
I believe that the problem was the bug in x64 ctypes module. I had Python 2.7 x64 installed and with that version following line (from script that I linked in question):
ctypes.windll.kernel32.SetConsoleTextAttribute(std_out_handle, code)
returns error code 6 with description The handle is invalid. After some investigation, I deduced that problem might be x64 version of python, so I installed 32-bit version and everything works as expected.
Since this solves my problem, and I do not have the time for deeper analysis I will leave it at this, just wanted to give some kind of resolution for question.
i install a web2py on my machine. i simply click on web2py.exe then it asking for password then it says "unable to detect your browser".
Any help will be appreciable.
This is not an error, it is just a warning message.
This message is being introduced by this line which propose is just to open the web browser automatically.
But, even without webbrowser module you should be able to run web2py and ignore the warning message,
If you are unable to run web2py or having any trouble, please open an issue ticket and web2py developers will look in to it.
The message is coming from here:
def try_start_browser(url):
""" Try to start the default browser """
try:
import webbrowser
webbrowser.open(url)
except:
print 'warning: unable to detect your browser'
You might try the webbrowser.open from a python cli shell to see what the specific exception is. On my (OS X) system:
~ $ python
Python 2.7.1 (r271:86882M, Nov 30 2010, 10:35:34)
[GCC 4.2.1 (Apple Inc. build 5664)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import webbrowser
>>> webbrowser.open('http://stackoverflow.com')
True