Develop Reference

Trouble getting Python Appium-Android test to work (connection error)

I am trying to run a Python Appium test. I have all the correct things installed on my Ubuntu machine (Android Studio, Appium, drivers, etc).
When I run the Python script (after starting Appium), I get this error:
selenium.common.exceptions.WebDriverException: Message: An unknown server-side error occurred while processing the command. Original error: Failed to connect 30 times. Aborting.
Stacktrace:
UnknownError: An unknown server-side error occurred while processing
the command. Original error: Failed to connect 30 times. Aborting.
at getResponseForW3CError (/usr/local/lib/node_modules/appium/node_modules/appium-base-driver/lib/protocol/errors.js:804:9)
at asyncHandler (/usr/local/lib/node_modules/appium/node_modules/appium-base-driver/lib/protocol/protocol.js:380:37)
This is my code:
example.py:
import os
from appium.webdriver import Remote
from appium_flutter_finder.flutter_finder import FlutterElement, FlutterFinder
# Example
driver = Remote('http://127.0.0.1:4723/wd/hub', dict(
platformName='android',
automationName='flutter',
platformVersion='11',
deviceName='emulator-5554',
app='/home/ironmantis7x/AndroidStudioProjects/demoflutter_1/build/app/outputs/flutter-apk/app-debug.apk'
))
finder = FlutterFinder()
text_finder = finder.by_text('You have pushed the button this many times:')
text_element = FlutterElement(driver, text_finder)
print(text_element.text)
key_finder = finder.by_value_key("next_route_key")
goto_next_route_element = FlutterElement(driver, key_finder)
print(goto_next_route_element.text)
goto_next_route_element.click()
back_finder = finder.page_back()
back_element = FlutterElement(driver, back_finder)
back_element.click()
tooltip_finder = finder.by_tooltip("Increment")
driver.execute_script('flutter:waitFor', tooltip_finder, 100)
floating_button_element = FlutterElement(driver, tooltip_finder)
floating_button_element.click()
counter_finder = finder.by_value_key("counter")
counter_element = FlutterElement(driver, counter_finder)
print(counter_element.text)
I am not sure why the session is not connecting. I see the app in the emulator open up.

teradatasql Python module only works when scripting but not when running code

I have run into a peculiar issue while using the teradatasql package (installed from pypi). I use the following code (let's call it pytera.py) to query a database:
from dotenv import load_dotenv
import pandas as pd
import teradatasql
# Load the database credentials from .env file
_ = load_dotenv()
db_host = os.getenv('db_host')
db_username = os.getenv('db_username')
db_password = os.getenv('db_password')
def run_query(query):
"""Run query string on teradata and return DataFrame."""
if query.strip()[-1] != ';':
query += ';'
with teradatasql.connect(host=db_host, user=db_username,
password=db_password) as connect:
df = pd.read_sql(query, connect)
return df
When I import this function in the IPython/Python interpreter or in Jupyter Notebook, I can run queries just fine like so:
import pytera as pt
pt.run_query('select top 5 * from table_name;')
However, if I save the above code in a .py file and try to run it, I get an error message most of the time (not all the time). The error message is below.
E teradatasql.OperationalError: [Version 16.20.0.49] [Session 0] [Teradata SQL Driver] Hostname lookup failed for None
E at gosqldriver/teradatasql.(*teradataConnection).makeDriverError TeradataConnection.go:1046
E at gosqldriver/teradatasql.(*Lookup).getAddresses CopDiscovery.go:65
E at gosqldriver/teradatasql.discoverCops CopDiscovery.go:137
E at gosqldriver/teradatasql.newTeradataConnection TeradataConnection.go:133
E at gosqldriver/teradatasql.(*teradataDriver).Open TeradataDriver.go:32
E at database/sql.dsnConnector.Connect sql.go:600
E at database/sql.(*DB).conn sql.go:1103
E at database/sql.(*DB).Conn sql.go:1619
E at main.goCreateConnection goside.go:229
E at main._cgoexpwrap_e6e101e164fa_goCreateConnection _cgo_gotypes.go:214
E at runtime.call64 asm_amd64.s:574
E at runtime.cgocallbackg1 cgocall.go:316
E at runtime.cgocallbackg cgocall.go:194
E at runtime.cgocallback_gofunc asm_amd64.s:826
E at runtime.goexit asm_amd64.s:2361
E Caused by lookup None on <ip address redacted>: server misbehaving
I am using Python 3.7.3 and teradatasql 16.20.0.49 on Ubuntu (WSL) 18.04.
Perhaps not coincidentally, I run into a similar issue when trying a similar workflow on Windows (using the teradata package and the Teradata Python drivers installed). Works when I connect inside the interpreter or in Jupyter, but not in a script. In the Windows case, the error is:
E teradata.api.DatabaseError: (10380, '[08001] [Teradata][ODBC] (10380) Unable to establish connection with data source. Missing settings: {[DBCName]}')
I have a feeling that there's something basic that I'm missing, but I can't find a solution to this anywhere.

Thanks ravioli for the fresh eyes. Turns out the issue was loading in the environment variables using dotenv. My module is in a Python package (separate folder), and my script and .env files are in the working directory.
dotenv successfully reads in the environment variables (.env in my working directory) when I run the code in my original post, line by line, in the interpreter or in Jupyter. However, when I run the same code in a script, it does not find in the .env file in my working directory. That will be a separate question I'll have to find the answer to.
import teradatasql
import pandas as pd
def run_query(query, db_host, db_username, db_password):
"""Run query string on teradata and return DataFrame."""
if query.strip()[-1] != ';':
query += ';'
with teradatasql.connect(host=db_host, user=db_username,
password=db_password) as connect:
df = pd.read_sql(query, connect)
return df
The code below runs fine in a script now:
import pytera as pt
from dotenv import load_dotenv()
_ = load_dotenv()
db_host = os.getenv('db_host')
db_username = os.getenv('db_username')
db_password = os.getenv('db_password')
data = pt.run_query('select top 5 * from table_name;', db_host, db_username, db_password)

It looks like your client can't find the Teradata server, which is why you see that DBCName missing error. This should be the "system name" of your Teradata server (i.e. TDServProdA).
A couple things to try:
If you are trying to connect directly with a hostname, try disabling COP discovery in your connection with this flag: cop = false. More info
Try updating your hosts file on your local system. From the documentation:
Modifying the hosts File
If your site does not use DNS, you must define the IP address and the
Teradata Database name to use in the system hosts file on the
computer.
Locate the hosts file on the computer. This file is typically located in the following folder: %SystemRoot%\system32\drivers\etc
Open the file with a text editor, such as Notepad.
Add the following entry to the file: xxx.xx.xxx.xxx sssCOP1 where xxx.xx.xxx.xxx is the IP address and where sss is the Teradata
Database name.
Save the hosts file.
Link 1
Link 2

python - java.lang.Exception: Class oracle.jdbc.driver.OracleDriver not found

Being a newbie to python, trying to write a python code to connect to the oracle database without using any Instant client. i'm using jaydebeapi and jpype as suggested in some other threads in this forum. After lot of hurdles, i now got stuck at this error. here is the code.
import jaydebeapi
import jpype
try:
con = jaydebeapi.connect('oracle.jdbc.driver.OracleDriver', ['windb19.ams.com', 'AA3112D1OS', 'advantage', 'C:\Tools\ojdbc8.jar'])
cur = con.cursor()
cur.execute('select * from r_sc_user_info')
except Exception as e:
print e
and the error i'm receiving is as below
C:\Python27\python.exe C:/Project/Robot_Framework/SampleProject/CustomLibraries/DBLibrary.py
java.lang.Exception: Class oracle.jdbc.driver.OracleDriver not found
Process finished with exit code 0

As I couldn't modify anything in the Environment variables, as per the policy, I had to modify the code as below to make it work. I had to keep the ojdbc8.jar in the same path as that of this python file and add following lines of code.
jar=os.getcwd()+'\ojdbc8.jar'
args = '-Djava.class.path=%s' % jar
jvm_path = jpype.getDefaultJVMPath()
jpype.startJVM(jvm_path, args)
try:
con = jaydebeapi.connect("oracle.jdbc.driver.OracleDriver", "jdbc:oracle:thin:#HOSTNAME",["USERID", "PASSWORD"], jar)

How to execute code when a Python script is closed out?

I have a raspberry pi that records temperature and stores them in a MySQL database on my website. I often toy with the script, so I am hitting ctrl+c on the running script and re executing it. I would like to properly issue close() on the database connection. How can I run a line of code when the script is exited in python?
import MySQLdb
con = MySQLdb.connect(...)
cursor = con.cursor()
# ...
#if script closes:
#con.close()

import MySQLdb
con = MySQLdb.connect(...)
cursor = con.cursor()
try:
# do stuff with your DB
finally:
con.close()
The finally clause is executed on success as well as on error (exception).
If you hit Ctrl-C, you get a KeyboardInterrupt exception.

or:
import atexit
def close_db(con):
con.close()
# any other stuff you need to run on exiting
import MySQLdb
con = MySQLdb.connect(...)
# ...
atexit.register(close_db, con=con)
See here for more info.

can't execute '.read create.sql'

This might be an obvious error but I'm trying to create a database within python from a script I've already created.
conn = sqlite3.connect('testDB')
c = conn.cursor()
c.execute('.read create.sql')
This gives an error "sqlite3.OperationalError: near ".": syntax error"
If I do the same thing at the sqlite3 cmd line it works fine
[me#myPC ~]$ sqlite3 testDB
SQLite version 3.3.6
Enter ".help" for instructions
sqlite> .read create.sql
sqlite>
It seems that any commands that start with a . give me problems.

just pass the content of the file to the .execute method:
conn = sqlite3.connect('testDB')
c = conn.cursor()
SQL = open('create.sql').read()
c.executescript(SQL)

I would suppose that commands starting with . are for the CLI client itself, not for the backend.
So you have no chance to do so and would have to do file reading and executing the queries by yourself, i.e. in Python.