CODEWITHSUNDEEP
pythonpython-3.x
victorR
victorR

Reputation: 139

how to get Leading Zeros in integer composed from items on a list Python

I am trying to create a six digit number constructed from serval modbus registers. I have no idea how modbus register work but was able to map certain numbers to decimal values.

Example: 

'12336': '00', 
'12592': '01', 
'12848': '02', 
'13104': '03',
.
.
.
'14649': '99'

I created a dictionary holding the full list of number from 00 to 99, I start reading 3 holdng registers and iterate over them and create an empty list that gets populated with the value corresponding to the key : value pair in the dictionary then I join them and cast to integer hoping to get the 6 digit number. It kind of works only if i have no leading zeros on my number, however if i do get leading zeros my number gets cut down to where that significant number start.

My code: 

NUMBERS  = {
    '12336': '00', '12592': '01', '12848': '02', '13104': '03', '13360': '04', '13616': '05', '13872': '06', '14128': '07', '14384': '08', '14640': '09', '12337': '10',

    }




def scanned_code():
    code = client.read_holding_registers(1, 3, unit=0)
    r = code.registers
    print(r)
    value = []

    for i in r :
        value.append(NUMBERS[str(i)])
    return value

def numb(lista):
    print(lista)
    res = int("".join(map(str, lista)))
    return res



scan_job = numb(scanned_code())
print(scan_job)

Let's say I have 3 holding registers with the following values: 12336, 13360, 14128 I would spect to generate this number 000407. instead I get 407

Actual values it get in terminal when executing script 

[12592, 13360, 14128]
['01', '04', '07']
10407

[12336, 13360, 14128]
['00', '04', '07']
407

Upvotes: 1

Views: 442

Answers (1)

Draconis
Draconis

Reputation: 3461

In Python (and pretty much any other programming language), numbers are stored as binary integers. So the concept of "leading zeroes" is meaningless: to the computer, 123 and 000123 would be stored exactly the same. (And, indeed, a mathematician would say those represent exactly the same value.)

If you want leading zeroes, you should store the value as a string. Just remove the int call within your numb function.

Upvotes: 3

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