Error : can't read /var/mail/std_msgs.msg

hi guys, i’m trying to execute a python code in my rosject but i’m facing this problem(can’t read /var/mail/std_msgs.msg and can’t read /var/mail/geometry_msgs.msg)
i don’t know what to do here’s a part of my code :

import rospy
from std_msgs.msg import String, Float64
from geometry_msgs.msg import Twist, Pose
import sys, getopt, math

class cmdvel2gazebo:
class cmdvel2gazebo:

def __init__(self,ns):
    self.ns = ns
    rospy.init_node('cmdvel2gazebo', anonymous=True)

    # the format(ns) looks for the namespace in the ros parameter server, I guess
    rospy.Subscriber('/catvehicle/cmd_vel_safe', Twist, self.callback)
    self.pub_steerL = rospy.Publisher('/catvehicle/front_left_steering_position_controller/command', Float64, queue_size=1)
    self.pub_steerR = rospy.Publisher('/catvehicle/front_right_steering_position_controller/command', Float64, queue_size=1)


Did you source the ros environment?
Although this imprts don’t seem to reffere to ROS, so could maybe share your ROSject here so we can debug it?