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Python

Chen Wang
Chen Wang
7,371 Points
Posted by Chen Wang
Chen Wang
7,371 Points

Macro challenge

Create a macro named hide_email. It should take a User as an argument. Print out the email attribute of the User in the following format: t***@example.com for the email test@example.com. This will require splitting the email string and using a for loop.

lunch.py 
from flask import Flask, render_template

app = Flask(__name__)

@app.route('/')
def index():
    class User:
        email = None
    user = User()
    user.email = 'kenneth@teamtreehouse.com'
    return render_template('user.html', user=user)
templates/macro.html 
{% macro hide_email(User) %}
  {% part1, part2 = User.email.split('@')%}
  {%result=part1[0]%}
  {%for cha in part1%}
    {% if cha!=part1[0]%}
      result= result+'*'
    {endif}
  {%endfor%}
  {%result= result+ '@' + part2%}

  <div>{{result}}</div>
{% endmacro %}

I have viewed other users' answers to this question and it still doesn't work for me. Because the system just keeps saying "try again", I really have no idea what is wrong. Is this a little bit unreasonable?

Even our code has bugs, can the system just say something to help us debug?

Anyway, anyone has idea about this problem, I need your help...

3 Answers

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

This challenge does have some issues with reporting errors. I tested methods out in Workspaces to get better feedback. Here's one of the ones I came up with that uses a loop:

{%- macro hide_email(user) -%}
  {#- Get the first letter of the email -#}
  {{user.email[0]}}
  {#- Get all the letters after the first, but before the @ -#}
  {%- for letter in user.email.split('@')[0][1:] -%}
    {{'*'}}
  {%- endfor -%}
  {#- Append the rest of the email on -#}
  {{ '@' + user.email.split('@')[1] }}
{%- endmacro -%}

You'll notice I avoided assignment. Assignment in Jinja is a bit different than in Python and wasn't covered in this course. If you want to go that route though, you can. I find it easier to follow than the loop method:

{% macro hide_email(user) %}
{%- set handle, domain = user.email.split("@") -%}
{%- set hidden = handle[0] + ("*" * handle[1:]|length) -%}
{{ hidden + "@" + domain }}
{%- endmacro %}

With Jinja, when you're dealing with output (stuff to be rendered in the HTML) use {{ }} over {% %}.

Chen Wang
Chen Wang
7,371 Points
Chen Wang
Chen Wang
7,371 Points

Cool Dan! Thanks a lot!

Ivars Jaundzeikars
Ivars Jaundzeikars
8,224 Points

Basically the key is to use '-' to avoid extra spacing in the for loop {%- for letter in user.email.split('@')[0][1:] -%} {{'*'}} {%- endfor -%}

that's if you same as I did failed due to extra spacing http://jinja.pocoo.org/docs/dev/templates/ "You can also strip whitespace in templates by hand. If you add a minus sign (-) to the start or end of a block (e.g. a For tag), a comment, or a variable expression, the whitespaces before or after that block will be removed:"

Well played

Khem Myrick
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Khem Myrick
Python Web Development Techdegree Graduate 18,701 Points
Khem Myrick
.a{fill-rule:evenodd;}techdegree seal-36
Khem Myrick
Python Web Development Techdegree Graduate 18,701 Points

I don't know what background settings are implied in that challenge, but I was able to get Dan's solution to work without any of the '-' characters or modified spacing, since I'm not 100% on what those do or how they work, and I wasn't sure how to google the question. The test did seem very particular about only using single quotes and not double quotes? Anybody know if that's a jinja/flask/python/html thing?

David Lin
David Lin
35,864 Points
David Lin
David Lin
35,864 Points

This also passes:

{% macro hide_email(user)%}
  {% set name, domain = user.email.split('@') %}
  {% set stars = (name|length - 1) * '*' %}
    {{ name[0] + stars + '@' + domain }}
{% endmacro %}
Pablo Xabron
Pablo Xabron
8,111 Points
Pablo Xabron
Pablo Xabron
8,111 Points

Here's my solution

def hide_email(email):
    se =  email.split('@')
    return se[0][0] + ''.join(['*' for _ in se[0][1:]]) + "@" + se[1]
Jing Zhang
Jing Zhang
Courses Plus Student 6,465 Points
Jing Zhang
Jing Zhang
Courses Plus Student 6,465 Points

This is a question about jinja, not python.