What are the differences between these built-in Python data types: list, sequence and slice? As I see it, all three essentially represent what C++ and Java call array.
I am using Python with PLY to parse LISP-like S-Expressions and when parsing a function call there can be zero or more arguments. How can I put this into the yacc code. This is my function so far:
def p_EXPR(p):
'''EXPR : NUMBER
| STRING
| LPAREN funcname [EXPR] RPAREN'''
if len(p) == 2:
p[0] = p[1]
else:
p[0] = ("Call", p[2], p[3:-1])
I need to replace "[EXPR]" with something that allows zero or more EXPR's. How can I do this?
Is there any way other than creating a method myself to write XML using python which are easily readable? xMLFile.write(xmlDom.toxml()) does create proper xml but reading them is pretty difficult. I tried toprettyxml but doesn't seem like it does much. e.g. following is what I would consider a human readable xml:
I have written a simple python module, it has this code:
_log = logging.getLogger("mymodule")
_started = False
def set_log_level(level):
_log.setLevel(level)
if not _started:
_hdlr = logging.FileHandler('mymodule.log')
When I call set_log_level() program fails because symbol _started is not found. It is normal because global _started is missing in the method. But my question is: symbol _log has the same visibility as _started, so why does this symbol can be found?
BR,
// Toby
What sort of mime type should I be using to email a .avi file from an automated python script? There are specific ones for audio/images, but not video afaik.
Hello,
Is there a way to declare a string variable in python such that everything inside of it is automatically escaped, or has its literal character value? I'm NOT asking how to escape the quotes with slashes, that's obvious. What I'm asking for is a general purpose way for making EVERYTHING in a string literal so that I don't have to manually go through and escape everything for very large strings. Anyone know of a solution? Thanks!
Hello everyone,
How can I get the file name and line number in python script.
Exactly the file information we get from an exception traceback. In this case without raising an exception.
Hey, here's a dumb question: how can I set an object property given its name in a string. I have a dictionary being passed to me and I wish to transfer its values into namesake properties using code like this:
for entry in src_dict:
if entry.startswith('can_'):
tgt_obj[entry] = src_dict_profile[entry]
I'm still a bit of a noob with Python so would appreciate some help.
- dave.
Hi, I'm developing C extensions from python ad I obtain some segfaults (inevitable during the development...).
I'm searching a way to display at which line of code the segfault happens (an idea is like tracing every single line of code), how I can do that?
Hi there,
I have a piece of text that gets handed to me like:
here is line one\n\nhere is line two\n\nhere is line three
What I would like to do is break this string up into three separate variables.
I'm not quite sure how one would go about accomplishing this in python.
Thanks for any help,
jml
This whole topic is way out of my depth, so forgive my imprecise question, but I have two computers both connected to one LAN.
What I want is to be able to communicate one string between the two, by running a python script on the first (the host) where the string will originate, and a second on the client computer to retrieve the string.
What is the most efficient way for an inexperienced programmer like me to achieve this?
I am trying to get the response codes from Mechanize in python. While I am able to get a 200 status code anything else isn't returned (404 throws and exception and 30x is ignored). Is there a way to get the original status code?
Thanks
How can I parse text and find all instances of hyperlinks with a string? The hyperlink will not be in the html format of <a href="http://test.com">test</a> but just http://test.com
Secondly, I would like to then convert the original string and replace all instances of hyperlinks into clickable html hyperlinks.
I found an example in this thread:
Easiest way to convert a URL to a hyperlink in a C# string?
but was unable to reproduce it in python :(
Using python and wsgiref.handlers, I can get a single variable from a form with self.handler.request.get(var_name), but how do I iterate through all form variables, be they from GET and POST? Is it something like this?
for field in self.handler.request.fields:
value = self.handler.request.get(field)
Again, it should include both fields included in the POST and fields from the query string, as in a GET request.
Thanks in advance folks...
I was working with Python with a Linux terminal screen. When I typed:
help(somefunction)
It printed the appropriate output, but then my screen was stuck, and at the bottom of the terminal was "(end)".
How do I get unstuck? Thanks in advance.
I have a few questions about python
I've seen many pages like these on Google
http://mail.google.com/support/bin/answer.py?answer=6583
https://www.google.com/adsense/support/bin/topic.py?topic=13488
...that have .py extensions. 1: Are pages like these built on pure python code, but printing out html like print "<div etc..." or like the typical asp,jsp,php type of pages with html pages and embedded python code like:
<html>
<% some python code %>
</html>
2: What is python mainly used for making? windows apps or web or .. ?
3: Are ruby and perl also similar to python?
What's the best way of getting the last item from an iterator in Python 2.6? For example, say
my_iter = iter(range(5))
What is the shortest-code / cleanest way of getting 4 from my_iter?
I could do this, but it doesn't seem very efficient:
[x for x in my_iter][-1]
The greenlet package is used by gevent and eventlet for asynchronous IO. It is written as a C-extension and therefore doesn't work with Jython or IronPython. If performance is of no concern, what is the easiest approach to implementing the greenlet API in pure Python.
A simple example:
def test1():
print 12
gr2.switch()
print 34
def test2():
print 56
gr1.switch()
print 78
gr1 = greenlet(test1)
gr2 = greenlet(test2)
gr1.switch()
Should print 12, 56, 34 (and not 78).
I write a python class which makes asynchronous method calls using D-Bus. When my reply_handler is called, it stores data in list. This list can be used by another class methods at the same time. Is it safe or I can use only synchronized data structures like Queue class?
I am building a python application to pull data from a website. The application has to authenticate(HTTPS/SSL) with a CAC card and pin in order to make requests.
Am I correct in my assumptions that you can't retrieve the private key from a CAC card, and am therefore stuck using a PKCS #11 Wrapper like PyKCS?
Any tips or resources for going about this?
Format is like:
CHINA;2002-06-25 00:00:00.000;5,60
CHINA;2002-06-26 00:00:00.000;5,32
CHINA;2002-06-27 00:00:00.000;5,31
and I try to use Python's CSV tools to parse it but cannot understand the paragraph, source:
And while the module doesn’t directly support parsing strings, it can easily be done:
import csv
for row in csv.reader(['one,two,three']):
print row
Could someone clarify the line ['one,two,three']? How would you use it with format A;B;C?
Hi,
I am planning to write a generic python module for installing a package. This script should retrieve the module from a remote machine or locally and install it on a given host and user. However, there needs to be changes made to the package files based on the host, user and given environment.
My approach is to use XML to describe changes to be made to package files based on environment. It will first extract the package to the user directory and then using an xml configuration file, it should replace the file values in the package directory. The xml would look something like this:
<package version="1.3.3">
<environment type="prod">
<file dir="d1/d2" name="f1">
<var id="RECV_HOST" value="santo">
<var id="RECV_PORT" value="RECV_PORT_SERVICE" type="service">
<var id="JEPL_SERVICE_NAME" value="val_omgact">
</file>
<var dir="d4/d3/s2" name="f2">
<var id="PRECISION" value="true">
<var id="SEND_STATUS_CODE" value="323">
<var id="JEPL_SERVICE_NAME" value="val_omgact">
</file>
</environment>
<environment type="qa">
<file dir="d1/d2" name="f1">
<var id="RECV_HOST" value="test">
<var id="RECV_PORT" value="1444">
<var id="JEPL_SERVICE_NAME" value="val_tsdd">
</file>
<file dir="d4/d3/s2" name="f2">
<var id="PRECISION" value="false">
<var id="SEND_STATUS_CODE" value="323">
<var id="JEPL_SERVICE_NAME" value="val_dsd">
</file>
</environment>
</package>
What are your thoughts on this approach? Is there an existing python module, package or script that I could use for this purpose since this seems fairly generic and can be used for any installation.
Thanks!
Sam
Hello everyone, i'm looking for a way in python to run an external binary and watch it's output for: "up to date" If "up to date" isn't returned i want to run the original command again, once "up to date" is displayed i would like to be able to run another script. So far I've figured out how to run the binary with options using subprocess but thats as far as I've gotten. Thanks!
I have a text document that contains a list of numbers and I want to convert it to a list. Right now I can only get the entire list in the 0th entry of the list, but I want each number to be an element of a list. Does anyone know of an easy way to do this in Python?
1000
2000
3000
4000
to
['1000','2000','3000','4000']