flask uses the jinja module, just call it directly, as follows

In [5]: from jinja2 import Template

In [6]: template = Template('{% for n in Data %} {{ n}} {% endfor %}')

In [7]: Data = range(10)
   ...: 

In [8]: template.render(Data=Data)
   ...: 
Out[8]: u' 0  1  2  3  4  5  6  7  8  9 '

Reference: http://docs.jinkan.org/docs/j...

Using render_template_string 即可, 传参方式和 render_template is similar, except that the first parameter is the read template content, not the template file path
The sample code is as follows (short demonstration, no routing is written, directly use app_context to simulate access):

from flask import (
    Flask,
    render_template_string
)

app = Flask(__name__)
tpl_args = {
    'Data': [1, 2, 3, 4, 5]
}
with app.app_context():
    result = render_template_string('{% for n in Data %} {{ n }} {% endfor %}', **tpl_args)
    print(result)

The output is as follows: