Stop Jinja2 Execution With IF Statement?











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0
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I have some code like:



{% if key_var is not none %}

  {{ my_list[key_var] }}

{% endif %}


However, I'm getting an error:



jinja2.exceptions.UndefinedError: 'list object' has no attribute 'None'


Is there a way to get Jinja2 to not run the code if the IF statement is false? Or am I missing something else?



Thank you for your help :)






django flask jinja2







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  • Why not {% if key_var %} and leave it at that?
    – dfundako
    Nov 8 at 18:20












  • That snippet works for me on the latest Jinja2 (2.10). What version of Jinja2 are you using? And are you sure that that fragment is the culprit?
    – Dave W. Smith
    Nov 8 at 18:35










  • @dfundako Because zero would do the wrong thing
    – Dave W. Smith
    Nov 8 at 18:38










  • I'm using Jinja2 2.9.6. I'll see if I can upgrade to 2.10.
    – VFR292
    Nov 9 at 3:32















up vote
0
down vote

favorite












I have some code like:



{% if key_var is not none %}

  {{ my_list[key_var] }}

{% endif %}


However, I'm getting an error:



jinja2.exceptions.UndefinedError: 'list object' has no attribute 'None'


Is there a way to get Jinja2 to not run the code if the IF statement is false? Or am I missing something else?



Thank you for your help :)






django flask jinja2







share|improve this question
























  • Why not {% if key_var %} and leave it at that?
    – dfundako
    Nov 8 at 18:20












  • That snippet works for me on the latest Jinja2 (2.10). What version of Jinja2 are you using? And are you sure that that fragment is the culprit?
    – Dave W. Smith
    Nov 8 at 18:35










  • @dfundako Because zero would do the wrong thing
    – Dave W. Smith
    Nov 8 at 18:38










  • I'm using Jinja2 2.9.6. I'll see if I can upgrade to 2.10.
    – VFR292
    Nov 9 at 3:32













up vote
0
down vote

favorite









up vote
0
down vote

favorite











I have some code like:



{% if key_var is not none %}

  {{ my_list[key_var] }}

{% endif %}


However, I'm getting an error:



jinja2.exceptions.UndefinedError: 'list object' has no attribute 'None'


Is there a way to get Jinja2 to not run the code if the IF statement is false? Or am I missing something else?



Thank you for your help :)






django flask jinja2







share|improve this question















I have some code like:



{% if key_var is not none %}

  {{ my_list[key_var] }}

{% endif %}


However, I'm getting an error:



jinja2.exceptions.UndefinedError: 'list object' has no attribute 'None'


Is there a way to get Jinja2 to not run the code if the IF statement is false? Or am I missing something else?



Thank you for your help :)






django flask jinja2




django flask jinja2






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 8 at 18:17

























asked Nov 8 at 17:47









VFR292

1314




1314












  • Why not {% if key_var %} and leave it at that?
    – dfundako
    Nov 8 at 18:20












  • That snippet works for me on the latest Jinja2 (2.10). What version of Jinja2 are you using? And are you sure that that fragment is the culprit?
    – Dave W. Smith
    Nov 8 at 18:35










  • @dfundako Because zero would do the wrong thing
    – Dave W. Smith
    Nov 8 at 18:38










  • I'm using Jinja2 2.9.6. I'll see if I can upgrade to 2.10.
    – VFR292
    Nov 9 at 3:32


















  • Why not {% if key_var %} and leave it at that?
    – dfundako
    Nov 8 at 18:20












  • That snippet works for me on the latest Jinja2 (2.10). What version of Jinja2 are you using? And are you sure that that fragment is the culprit?
    – Dave W. Smith
    Nov 8 at 18:35










  • @dfundako Because zero would do the wrong thing
    – Dave W. Smith
    Nov 8 at 18:38










  • I'm using Jinja2 2.9.6. I'll see if I can upgrade to 2.10.
    – VFR292
    Nov 9 at 3:32
















Why not {% if key_var %} and leave it at that?
– dfundako
Nov 8 at 18:20






Why not {% if key_var %} and leave it at that?
– dfundako
Nov 8 at 18:20














That snippet works for me on the latest Jinja2 (2.10). What version of Jinja2 are you using? And are you sure that that fragment is the culprit?
– Dave W. Smith
Nov 8 at 18:35




That snippet works for me on the latest Jinja2 (2.10). What version of Jinja2 are you using? And are you sure that that fragment is the culprit?
– Dave W. Smith
Nov 8 at 18:35












@dfundako Because zero would do the wrong thing
– Dave W. Smith
Nov 8 at 18:38




@dfundako Because zero would do the wrong thing
– Dave W. Smith
Nov 8 at 18:38












I'm using Jinja2 2.9.6. I'll see if I can upgrade to 2.10.
– VFR292
Nov 9 at 3:32




I'm using Jinja2 2.9.6. I'll see if I can upgrade to 2.10.
– VFR292
Nov 9 at 3:32












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{% if my_list[key_var] is defined %}

  {{ my_list[key_var] }}

{% endif %}


Got the behavior I was looking for. I didn't want my_list[key_var] to run inside of the IF statement when the key_var is None



I don't know why this worked when my original attempt didn't. If anyone knows, please fill me in.



Thank you!






share|improve this answer





















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    up vote
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    {% if my_list[key_var] is defined %}
    
  {{ my_list[key_var] }}
    
{% endif %}


    Got the behavior I was looking for. I didn't want my_list[key_var] to run inside of the IF statement when the key_var is None



    I don't know why this worked when my original attempt didn't. If anyone knows, please fill me in.



    Thank you!






    share|improve this answer

























      up vote
      0
      down vote













      {% if my_list[key_var] is defined %}
      
  {{ my_list[key_var] }}
      
{% endif %}


      Got the behavior I was looking for. I didn't want my_list[key_var] to run inside of the IF statement when the key_var is None



      I don't know why this worked when my original attempt didn't. If anyone knows, please fill me in.



      Thank you!






      share|improve this answer























        up vote
        0
        down vote










        up vote
        0
        down vote









        {% if my_list[key_var] is defined %}
        
  {{ my_list[key_var] }}
        
{% endif %}


        Got the behavior I was looking for. I didn't want my_list[key_var] to run inside of the IF statement when the key_var is None



        I don't know why this worked when my original attempt didn't. If anyone knows, please fill me in.



        Thank you!






        share|improve this answer












        {% if my_list[key_var] is defined %}
        
  {{ my_list[key_var] }}
        
{% endif %}


        Got the behavior I was looking for. I didn't want my_list[key_var] to run inside of the IF statement when the key_var is None



        I don't know why this worked when my original attempt didn't. If anyone knows, please fill me in.



        Thank you!







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 9 at 4:06









        VFR292

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