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Python

Posted by Andreas cormack
.a{fill-rule:evenodd;}techdegree seal-36
Andreas cormack
Python Web Development Techdegree Graduate 33,011 Points

create a macro hide_email

this code logic runs in the python shell fine but cannot get it to work on this challenge anyone any ideas.

jinja2
{% macro hide_email(User) %}
  {% for User in Users %}
     {% before_the_at,after_the_at=User.email.split("@",1) %} #split the string on the @ sign """
     {% after_the_at="@"+after_the_at %} #all the @ sign to the second half of the string """
     {% email_format=""%} # setting a variable called email_format 
        {% for letter_count in range(0,len(before_the_at)) %} # looping through each letter in the string before_the_at
            {% if letter_count==0 %}# if the count is 0 or first letter add that to the string email_format
                {% email_format=before_the_at[0]%}
            {% else %}# else add **** to the end of the email_format string
                {%  email_format=email_format+"*" %}
        {% endfor %}
     {% email_format=email_format+after_at %} # lastly appending the after_at string to the email format
     {{% email_format %}}  

  {% endfor %}



{% endmacro %}

3 Answers

Dan Johnson
Dan Johnson
40,533 Points
Dan Johnson
Dan Johnson
40,533 Points

The embedded Python in Jinja2 has some syntax differences. For a solution similar to what you're going for:

{# Only one User is being sent in #}
{% macro hide_email(User) %} 
   {#- Use "set" to declare a variable -#}
   {%- set before_the_at, after_the_at = User.email.split("@") -%} 
   {%- set after_the_at = "@" + after_the_at -%} 
   {#- Use the "length" filter instead of the "len" function -#}
   {%- for letter_count in range(before_the_at|length) -%}  
        {%- if letter_count == 0 -%}
          {#- Attempting to assign to something set in an outer block will just shadow it with another variable. -#}
          {{before_the_at[0]}}
        {%- else -%}
            {{"*"}}
        {%- endif -%}
    {%- endfor -%} 
    {{after_the_at}}
{%- endmacro %}

I know the challenge mentions using a for loop, but if you want to use "set" you can shorten it to this:

{% macro hide_email(user) %}
{%- set handle, domain = user.email.split("@") -%}
{%- set hidden = handle[0] + ("*" * handle[1:]|length) -%}
{{ hidden + "@" + domain }}
{%- endmacro %}
Andreas cormack
.a{fill-rule:evenodd;}techdegree seal-36
Andreas cormack
Python Web Development Techdegree Graduate 33,011 Points

Thanks Dan that's was were helpful.

Dan Johnson
Dan Johnson
40,533 Points
Dan Johnson
Dan Johnson
40,533 Points

The | operator applies a filter, a modifier for the variable on the left. You can go here for a list of all built-in filters.

james white
james white
78,399 Points
james white
james white
78,399 Points

Hi Dan,

Thanks.

Your 'set' code was much more helpful than the information given in this other thread on the same challenge:

https://teamtreehouse.com/forum/splitting-the-string

Tom Drury
Tom Drury
10,546 Points
Tom Drury
Tom Drury
10,546 Points

Can someone explain the difference between using {% ... %} and {%- ... -%}. It seems to make a difference. thanks.

Dan Johnson
Dan Johnson
40,533 Points
Dan Johnson
Dan Johnson
40,533 Points

Adding the minus sign will remove whitespace from the generated HTML before or after (or both if you add the minus sign to both sides) the expression/block.

The template documentation under the "Whitespace Control" section has more info: http://jinja.pocoo.org/docs/dev/templates/#whitespace-control