Remove, avoid empty array,list being viewed

🎈 Using Streamlit
1

Hi,

I’m new using nice tool - streamlit and I would like to know how to avoid empty array or list be viewed.
I’m creating some pandas tables wich I can show without any problem with st.write() …
however, before the table, I see "empty " list with null values.
I have 12 like:
[…]
[
0:NULL
1:NULL
2:NULL
3:NULL
4:NULL
5:NULL
6:NULL
7:NULL
8:NULL
]
No idea why it appears if I do not have any st.func() for example.
Any help or guide is very appreciated - Thanks

2

Hi @Dicast, welcome to the Streamlit community!

I’m not sure I understand your question, could you be more specific? Maybe if you post a code snippet we can see what the issue is.

Best,
Randy

3

Hi Randy, tks for your reply.

st

I have uploaded an image. I think, it is easier, thereby, you can see the list/array empty being showed.
First func in my code related to streamlit, is st.title(‘Starting at:’,time), but, you can see some list before it. Also, after before next streamlit func which would be: st.write() with may pandas table “Dole”.
I´m running for loops without function, I think the interaction could be logged on streamlit through those lists… Just let me know if you need more details, please.
Thanks

4

Yes, I’m still not understanding what your desired output is. If you can post the code you are using, then it will be more helpful.

5

Hi Randy,

I have posted an image in order to try explain it better,.

st
st1065×479 30.1 KB

thanks in advance!

6

Basically, I just want to remove those empty lists\array and show what I choose through streamlit´s funcions like:
st.text(), st.write() for example.

7

Please post your code. Without knowing where the empty lists come from, I can’t tell you how to fix it.

8

Hello, today I faced the same issue, I was able to resolve it by modifying a list comprehension with a more “classic” for loop.

9

I have classic loops but still facing this same issue.

10

Did you manage to remove those empty lists/arrays? Let me know.

11

As mentioned above, the fastest way to tell you where the issue is would be to post the code. This isn’t a weird quirk of Streamlit, but likely a tiny logic error.

12

I had the same problem. After reading randyzwitch’s answer I played around with my function and I found that it was displaying the output of a list comprehension. Even though the list comprehension is inside a function and wouldn’t display as an output in my IDE.

xlistnodup =[ ]
[xlistnodup.append(x) for x in xlist if x not in xlistnodup]
return xlistnodup

creating a place for the output to land solved the problem.

x = [xlistnodup.append(x) for x in xlist if x not in xlistnodup]

1 Like
13

This is expected behavior. Streamlit renders most objects that exist on a line by themself by default. This includes a list, even if that list is defined through list comprehension.

14

I had the same problem. After reading randyzwitch’s answer I played around with my function and I found that it was displaying the output of a list comprehension. Even though the list comprehension is inside a function and wouldn’t display as an output in my IDE.

xlistnodup = [ ]
[xlistnodup.append(x) for x in xlist if x not in xlistnodup]
return xlistnodup

x = [xlistnodup.append(x) for x in xlist if x not in xlistnodup]

creating a place for the output to land solved the problem.

I followed this resolution and managed to resolve the issue.
Basically streamlit prints the output of the list comprehension.

15

I had the same problem. After reading randyzwitch’s answer I played around with my function and I found that it was displaying the output of a list comprehension. Even though the list comprehension is inside a function and wouldn’t display as an output in my IDE.

xlistnodup = [ ]
[xlistnodup.append(x) for x in xlist if x not in xlistnodup]
return xlistnodup

creating a place for the output to land solved the problem.

x = [xlistnodup.append(x) for x in xlist if x not in xlistnodup]
…
I followed this resolution and managed to resolve the issue.
Basically streamlit prints the output of the list comprehension.