Can't iterate PrettyDict of Pandas

[colspan]

Iterating the result of Pandas.DataFrame.groupby fails with pandas>=1.1.0.
This failure seems to be caused by PrettyDict which is the alternative type of dict and added on pandas==1.1.0.
The log shows that pycall.rb can't regard PrettyDict as dict.

Reproduction code

require 'pandas'
df = Pandas.DataFrame.new([['a', 1], ['a', 1], ['b', 2]])
df.groupby(0).groups.each do |name, value|
    p name, value
end

pandas<1.1.0

"a"
Int64Index([0, 1], dtype='int64')
"b"
Int64Index([2], dtype='int64')

pandas>=1.1.0

TypeError: unexpected Python type PrettyDict (expected dict)
/home/jovyan/.bundle/ruby/2.7.0/gems/pycall-1.3.1/lib/pycall/dict.rb:38:in `dict_each'
/home/jovyan/.bundle/ruby/2.7.0/gems/pycall-1.3.1/lib/pycall/dict.rb:38:in `each'
<main>:1:in `<main>'
/home/jovyan/.bundle/ruby/2.7.0/gems/iruby-0.4.0/lib/iruby/backend.rb:44:in `eval'
/home/jovyan/.bundle/ruby/2.7.0/gems/iruby-0.4.0/lib/iruby/backend.rb:44:in `eval'
/home/jovyan/.bundle/ruby/2.7.0/gems/iruby-0.4.0/lib/iruby/backend.rb:12:in `eval'
/home/jovyan/.bundle/ruby/2.7.0/gems/iruby-0.4.0/lib/iruby/kernel.rb:90:in `execute_request'
/home/jovyan/.bundle/ruby/2.7.0/gems/iruby-0.4.0/lib/iruby/kernel.rb:49:in `dispatch'
/home/jovyan/.bundle/ruby/2.7.0/gems/iruby-0.4.0/lib/iruby/kernel.rb:38:in `run'
/home/jovyan/.bundle/ruby/2.7.0/gems/iruby-0.4.0/lib/iruby/command.rb:110:in `run_kernel'
/home/jovyan/.bundle/ruby/2.7.0/gems/iruby-0.4.0/lib/iruby/command.rb:40:in `run'
/home/jovyan/.bundle/ruby/2.7.0/gems/iruby-0.4.0/bin/iruby:5:in `<top (required)>'
/home/jovyan/.gem/ruby/2.7.0/bin/iruby:23:in `load'
/home/jovyan/.gem/ruby/2.7.0/bin/iruby:23:in `<main>'