How to string format when string have { in Python?

Question

I have the following string:

nginx_conf = '''
server {
 listen 80;
 server_name dev.{project_url};

 location / {
 proxy_pass http://127.0.0.1:8080;
 include /etc/nginx/proxy.conf;
 }

 location /media {
 alias /home/mariano/PycharmProjects/{project_name}/{project_name}/media;
 expires 30d;

 }
 location /static {
 alias /home/mariano/PycharmProjects/{project_name}/{project_name}/static;
 expires 30d;
 }

 error_page 500 502 503 504 /50x.html;
 location = /50x.html {
 root html;
 }
}'''

And I want to format like this:

context = {
 "project_name":project_name,
 "project_url":project_url,
 }

nginx_conf.format(**context)

but since the string have { i can't. Is there a way to solve this?

Answer 1

Are you in full control of the source string? You can escape the braces as explained here:

https://docs.python.org/3.4/library/string.html#format-string-syntax

If you're not in full control (eg if it comes from a user's input), or if you don't like the idea of doubling all your braces, you could switch to percent-formatting, or some other form of interpolation. But the easiest would be to simply escape them.