Display content of files in a particular directory using Flask

I am implementing an app using Flask and I am trying to display the content of text files I put in log directory. So i have done this:

@app.route('/files', methods = ['GET'])
def config():
    if 'username' in session :
        path = os.path.expanduser(u'~/path/to/log/')
        return render_template('files.html', tree=make_tree(path))
    else:
        return redirect(url_for('login'))

def make_tree(path):
    tree = dict(name=os.path.basename(path), children=[])
    try: lst = os.listdir(path)
    except OSError:
        pass #ignore errors
    else:
        for name in lst:
            fn = os.path.join(path, name)
            if os.path.isdir(fn):
                tree['children'].append(make_tree(fn))
            else:
                tree['children'].append(dict(name=name))
    return tree

in my html page files.html:

<title>Path: {{ tree.name }}</title>
<h1>{{ tree.name }}</h1>

<div class="accordion-heading" >
    <div class="accordion-toggle" >
         <a data-toggle="collapse"  data-target="#files_list" href="#files_list">
            <b>

<ul>
{%- for item in tree.children recursive %}
 <div class="well well-sm">   <li>{{ item.name }} </div>
    {%- if item.children -%}
        <ul>{{ loop(item.children) }}</ul>
    {%- endif %}</li>
{%- endfor %}
</ul>

 </b></div>
         </a>
    </div>

This only displays the names of the files inside my log directory but I am not able to display the content of the files. I thought maybe I can use something like:

import fnmatch
def display_files():
    for dirpath, dirs, files in os.walk('log'):
        for filename in fnmatch.filter(files, '*.*'):
        with open(os.path.join(dirpath, filename)) as f:
            file_contents = f.read().strip()
            print file_contents

    return render_template('files.html',title="index",file_contents=file_contents) 

Any help please??