如何更新 Python 中的字典值？

Question

Trying to update a dict value, but somehow getting an error.

Here is my code:

print('issue.tags: ', issue.tags)
print(type(issue.tags))
for tag in issue.tags: # Compare eta with tag, to see if changed
    print('tag: ', tag)
    print(type(tag))
    print('tag.get("id", ""): ', tag.get('id', ''))
    print(type(tag.get('id', '')))
    if ('ETA' in tag.get('id', '')):
        try:
            oldETA = datetime.datetime.strptime(tag.get('id', '')[4:], '%Y-%m-%d')
        except:
            oldETA = str(tag.get('id', '')[4:])
        if (eta_cet != oldETA):
            etaChanged = True
            tag['id'][0] = ''.join(['ETA ', str(eta_cet)])

And here is what I get when executing the code:

issue.tags:  [{'id': 'ETA None'}]
<class 'list'>
tag:  {'id': 'ETA None'}
<class 'dict'>
tag.get("id", ""):  ETA None
<class 'str'>
Traceback (most recent call last):
  File "/home/karimbel/ABmktIntel/env/ABmktIntel-1.0/runtime/bin/hello.py", line 11, in <module>
    load_entry_point('ABmktIntel==1.0', 'console_scripts', 'hello.py')()
  File "/home/karimbel/ABmktIntel/env/ABmktIntel-1.0/runtime/lib/python3.6/site-packages/a_bmkt_intel/hello_world.py", line 64, in main
    commentIssueWithETA(results, sim)
  File "/home/karimbel/ABmktIntel/env/ABmktIntel-1.0/runtime/lib/python3.6/site-packages/a_bmkt_intel/hello_world.py", line 127, in commentIssueWithETA
    tag['id'][0] = ''.join(['ETA ', str(eta_cet)])
TypeError: 'str' object does not support item assignment

Anyone knows if I'm doing something wrong?

I want to change the string value from "ETA None" to "ETA + str(eta_cet)". str(eta_cet) is '2019-12-31'. So basically I want to have as a new value of tag id "ETA 2019-12-31".

Answer 1

If tag is a dict then tag['id'] refers to the string 'ETA None' .

Perhaps your assignment should be tag['id'] = ''.join(['ETA ', str(eta_cet)])