os system command not found

[codicedave]

Hi all!
I installed a external program called infomap using the classical
procedure

./configure
make
sudo make install

 and it works perfectly in Terminal (Os x) using both bash and tcsh
shell

admins-macbook-pro-2:~ unil$ infomap-build

Usage: infomap-build [-w working_dir] [-p param_file]
       [-D var_1=val_1 ... -D var_N=val_N]
       (-s single_corpus_file | -m multi_file_list)
       <model_tag>


 but when I call it from python using os.system or subprocess.call I
get the message "sh: infomap-build: command not found".

Do you know why?

Many thanks

Davide