We could change the code like this, so we can get at least some readings and can better determent where the error is. Just add Finally like this:

ReadData.py line: 20-35

def writeDATA(s):
try:
temp = sensor.read_temperature()
pascals = sensor.read_pressure()
press = pascals / 100
hum = sensor.read_humidity()
except:
print 'Sensor Error. Please try again.'
finally:
print str(temp)
print str(press)
print str(hum)

We need a config file.

as mentioned in the title, we need a config file for an easy setup process. There should be a config file for the Server and for the Client and should contain:
Client: - Server ip + Port
Custom PiIp
Some information about the sensor or which Data should be send to the server

Server:
His own ip + port
Database
Sensor and PiIp whitelist

Both should have an option to toggle the output completely

Hello,
The program needs to commit the data into the DB every time it receives data.
With the current setup the program wouldn't submit any Data to the db when it's running in infinity mode.

look at this:
http://www.pythonforbeginners.com/python-on-the-web/how-to-use-urllib2-in-python/
and this:
http://www.golem.de/news/mitmachprojekt-temperatur-messen-und-senden-mit-dem-raspberry-pi-1604-120188-3.html

We need a way to reset the TCP port before we establish a connection.
So we can close and reconnect to the server as often as we wish with out the need of an reboot.

Try and Except should be inplemented as often as possible in order to achieve usefull error messages.
for example:

• open/write to a file
• get data from sensor
  ...