“RuntimeError: dictionary keys changed during iteration” when attempting to call add_attachment

Arun Ajay

I am attempting to just add a CSV file to my issues as a test, but I keep receiving the error:

```
RuntimeError: dictionary keys changed during iteration
```

Here is the code (I've removed the parameters for server, username and password:
```
from jira import JIRA

options = {"server": "serverlinkgoeshere"}
jira = JIRA(options, basic_auth=('username', 'password'))
issuesList = jira.search_issues(jql_str='', startAt=0, maxResults=100)
for issue in issuesList:
with open("./csv/Adobe.csv",'rb') as f:
jira.add_attachment(issue=issue, attachment=f)
f.close()
```
I'm at a loss, I'm not changing any dictionary keys in my code. Here is the full error message:

```
Traceback (most recent call last):
File "C:/Users/USER/PycharmProjects/extractor/main/jiraCSVDupdate.py", line 8, in <module>
jira.add_attachment(issue=issue, attachment=f)
File "C:\Users\USER\AppData\Roaming\Python\Python38\site-packages\jira\client.py", line 126, in wrapper
result = func(*arg_list, **kwargs)
File "C:\Users\USER\AppData\Roaming\Python\Python38\site-packages\jira\client.py", line 787, in add_attachment
url, data=m, headers=CaseInsensitiveDict({'content-type': m.content_type, 'X-Atlassian-Token': 'nocheck'}), retry_data=file_stream)
File "C:\Users\USER\AppData\Roaming\Python\Python38\site-packages\jira\utils\__init__.py", line 41, in __init__
for key, value in super(CaseInsensitiveDict, self).items():
RuntimeError: dictionary keys changed during iteration
```

References:
Jira add_attachment example:
https://jira.readthedocs.io/en/master/examples.html#attachments

add_attachment source code:
https://jira.readthedocs.io/en/master/_modules/jira/client.html#JIRA.add_attachment

Nic Brough -Adaptavist-

You'll need to rework your python code so that it does not alter the object while it is running over it.

This is a slightly different error, but is the same solution - https://hackernoon.com/filtering-dictionary-in-python-3-3eb99f92e6ee