What is the best way to create a python script by calling which, it will ALWAYS generate a new UNIQUE ID (Auto-incremental)?
You run the script and it will tell you 1, then close script and open again and will tell you 2.
Purpose of it is to create a script which will be used across and this ID will be used to track the latest changes and so on.
P.S. I'm not talking to make a function which will do it.
I assume you have a script, it will generate some result every time it is executed. Then you need need a value that (1) distinguish one result from another and (2) shows which result came last. Is that right? If so, we have many options here. In the simplest case (a script always running in the same machine) I would suggest two options
In this case, you would have a file and would read the number from it:
try:
with open('count.txt') as count_file:
content = count_file.read()
count = int(content)
except Exception:
count = 0
After doing whatever your script does, you would write to the file the value you've read, but incremented:
with open('count.txt', 'w') as count_file:
count_file.write(str(count + 1))
A simpler option, however, is not to increment a value but get a timestamp. You could use time.time(), that returns the number of seconds since Unix epoch:
>>> import time
>>> time.time()
1547479233.9383247
You will always know which result came later than the others. Personally, however, I would rather format the current time, it is easier to read and reason about:
>>> from datetime import datetime
>>> datetime.now().strftime('%Y%m%d%H%M%S')
'20190114132407'
Those are basic ideas, you may need to pay attention to corner cases and possible failures (especially with the file-based solution). That said, I guess those are quite viable first steps.
What you want here is to a program to remember a piece of information between two or more executions, and we have a technical term for that: the information should be persistent. Since you asked for an autoincrementing feature, you wanted a persistent count. I suspect, however, you do not need that if you use the timestamp option. It is up to you to decide what to do here.
Since you didnt provide any code, I will also not provide any code.
Solution 1: Unique ID
1) TIME: create function to give you timestamp
2) ID: create function that generate long string with random numbers and letters
save in file or somewhere
Solution 2: offset - incremental
1) have file with a 0 in it.
2) open a file, read line, convert to integer, increment to +1, write in a file.
Note:
Your title is wrong. One moment you talk about UNIQUE ID, Next moment you are talking about offset. Unique ID and counting running python script are quite contradicting ideas
I had the same situation. I ended up in creating a CSV file so that I can map variable names.
def itemId_generator(itemIdLocation):
# Importing value of ItemID from the csv file
df = pd.read_csv(itemIdLocation)
#return value which is current ItemID in the csv file
ItemId = df.loc[0, 'ItemId']
# If loop to set limit to maximum Item ID
if ItemId>= 10000:
df.loc[0, 'ItemId'] = 1
elif ItemId<10000:
# updating the column value/data
df.loc[0, 'ItemId'] = df.loc[0,'ItemId'] + 1
else:
print("Invalid value returned")
sys.exit()
# writing new ItemID into the file
df.to_csv(itemIdLocation, index=False)
# The function .item() converts numpy integer to a normal int
return str(ItemId.item())
If there is any chance of the file being accessed concurrently, it is best to lock the file. Keep trying if the file is locked.
http://tilde.town/~cristo/file-locking-in-python.html
Old answer: You could store it as an environment variable on the system. If not set, initialise to 1. Else increment it by 1.
