B4J Question call a Python script in Raspberry Pi

[jcohedman]

I`m trying to read RFID in a Raspberry Pi.
If I run in the raspi: $ sudo python rfidle.py, functions...
But with B4j, not...
can anybody help me? Thanks!

Sub AppStart (Args() As String)
Dim sh As Shell

' sftp://pi@192.168.1.15/home/pi/pi-rc522/examples/rfidle.py

sh.Initialize("sh", "python", Array As String("rfidle.py", "w", "B4J is", "great"))
sh.WorkingDirectory = "/home/pi/pi-rc522/examples/"
sh.Run(10000)

StartMessageLoop
End Sub

Sub sh_ProcessCompleted (Success As Boolean, ExitCode As Int, StdOut As String, StdErr As String)
If Success And ExitCode = 0 Then
Log("Success")
Log(StdOut)
Else
Log("Error: " & StdErr)
End If
'ExitApplication

 

[Erel]

Please use [code]code here...[/code] tags when posting code.

What is the output?
Are you running B4J-Bridge with sudo?

 

[jcohedman]

Yes, sudo java -jar b4j-bridge.jar

Error log:
SyntaxError: invalid syntax

I was searching, and found that the problem is in the python script, it's recomended to do this:

print ("HelloWorld",flush=True)

but...

 

[Erel]

Also check the value of StdOut. It might include more information.

 

[wonder]

Note that print() is a Python 3+ function. In Python 2.7 print is a statement.
Examples:

#Python 2.7.x
print "Hello world!"

#Python 3.x
print("Hello world!")

http://sebastianraschka.com/Articles/2014_python_2_3_key_diff.html

 

[MaFu]

On my used Python 2 (2.7.13) print("Hello") works also.

 

[wonder]

On my used Python 2 (2.7.13) print("Hello") works also.

I didn't know about that. Thanks!

 

[jcohedman]

solved at "argentininan" style...

Python script:

#!/usr/bin/python3import sys

from pirc522 import RFID

import signal

import time

sys.path.insert(0, "/home/pi/pi-rc522/ChipReader")

rdr = RFID()

util = rdr.util()

util.debug = False

while True:

# Request tag(error, data) = rdr.request()

if not error:

# print ("\nDetected")(error, uid) = rdr.anticoll()

if not error:

file = open("foo.txt", "w")
file.write(str(uid[0])+str(uid[1])+str(uid[2])+str(uid[3]))
file.close() 
print (str(uid[0])+str(uid[1])+str(uid[2])+str(uid[3]))

time.sleep(1)

so, in B4J for raspberry:

Sub BuscarRFID_Action
    Dim shl As Shell
    shl.Initialize("shl", "python", Array As String("lectorRFID1.py"))
    shl.WorkingDirectory = "/home/pi"'
    shl.Run(500)
End Sub

Sub shl_ProcessCompleted (Success As Boolean, ExitCode As Int, StdOut As String, StdErr As String)
    If File.Exists("/home/pi", "foo.txt") Then
    Dim text As String
    text = File.ReadString("/home/pi", "foo.txt")
        If text.Length>5 Then
            Log("RFID: "&text)
            File.WriteString("/home/pi", "foo.txt"," ")
        End If
End If
End Sub