Python Screen Scraper works within Eclipse, but not from command line - eclipse

Question

I'm writing a simple screen scraping script using python 2.7 with Eclipse PyDev. When running or debugging from within Eclipse everything works fine. However, when I run my program from the command line the server always returns a Response 500 error code. I've tried running the script and the compiled versions from the command line but get the same result -- Response 500. I've also tried some arbitrary things like adding a delay, repeated attempts, etc. but I do not know what Eclipse is doing that is different than python ran the command line.
First, where's a good place to start digging if I encounter something like this again?
Second, any ideas on how to get this working from the command line?
Code snippet below for reference
from requests import Request, Session
content_type = 'application/x-www-form-urlencoded'
headers2 = {"User-Agent" : 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)',
"Content-Type" : content_type,
"Referer" : url
}
url = loginPage
payload = {"email" : username, "password" : password}
req = Request ('POST', url, data=payload, headers=headers2)
prepped = req.prepare()
s = Session()
resp = s.send(prepped)
print resp # Response 200 (good) from both within Eclipse and from cmd
resp = s.get(targetPage)
print resp # Response 200 (good) from Eclipse, Response 500 (generic web error) from cmd
s.get (logOutPage)
s.close()

Answer 1

Got an answer from somebody. Thanks go to user Justinsaccount from reddit.
First, I was using batch files to save typing and not directly using the command line.
Secondly, when printing out the parameters from inside the program and then comparing the eclipse version versus the .bat version, the .bat version was short a few characters which was the give away.
One of the parameters was a url that had a space character: http://somewhere.com/some page.
In strict URL, this turns into: http://somewhere.com/some%20page
When run from the command line http://somewhere.com/some%20page
works just fine. However, in a batch file the % needed to be escaped so what I got was: http://somewhere.com/some0page
which is why the server through an error -- that page didn't exist. What I needed to do was escape the % character: http://somewhere.com/some%%20page. After that change things worked just fine.