Why is the catkin_make command showing error?

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Output:

riddhi@riddhi-Inspiron-N5010:~/catkin_ws$ catkin_make
Base path: /home/riddhi/catkin_ws
Source space: /home/riddhi/catkin_ws/src
Build space: /home/riddhi/catkin_ws/build
Devel space: /home/riddhi/catkin_ws/devel
Install space: /home/riddhi/catkin_ws/install
####
#### Running command: "make cmake_check_build_system" in "/home/riddhi/catkin_ws/build"
####
####
#### Running command: "make -j4 -l4" in "/home/riddhi/catkin_ws/build"
####
../catkin_generated/env_cached.sh: 16: exec: /usr/local/bin/python: not found
beginner_tutorials/CMakeFiles/_beginner_tutorials_generate_messages_check_deps_AddTwoInts.dir/build.make:57: recipe for target 'beginner_tutorials/CMakeFiles/_beginner_tutorials_generate_messages_check_deps_AddTwoInts' failed
make[2]: *** [beginner_tutorials/CMakeFiles/_beginner_tutorials_generate_messages_check_deps_AddTwoInts] Error 127
CMakeFiles/Makefile2:784: recipe for target 'beginner_tutorials/CMakeFiles/_beginner_tutorials_generate_messages_check_deps_AddTwoInts.dir/all' failed
make[1]: *** [beginner_tutorials/CMakeFiles/_beginner_tutorials_generate_messages_check_deps_AddTwoInts.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
../catkin_generated/env_cached.sh: 16: exec: /usr/local/bin/python: not found
beginner_tutorials/CMakeFiles/_beginner_tutorials_generate_messages_check_deps_Num.dir/build.make:57: recipe for target 'beginner_tutorials/CMakeFiles/_beginner_tutorials_generate_messages_check_deps_Num' failed
make[2]: *** [beginner_tutorials/CMakeFiles/_beginner_tutorials_generate_messages_check_deps_Num] Error 127
CMakeFiles/Makefile2:656: recipe for target 'beginner_tutorials/CMakeFiles/_beginner_tutorials_generate_messages_check_deps_Num.dir/all' failed
make[1]: *** [beginner_tutorials/CMakeFiles/_beginner_tutorials_generate_messages_check_deps_Num.dir/all] Error 2
[  0%] Built target std_msgs_generate_messages_lisp
[  0%] Built target std_msgs_generate_messages_cpp
Makefile:138: recipe for target 'all' failed
make: *** [all] Error 2
Invoking "make -j4 -l4" failed