로보틱스 교수님 코드 리뷰 및 개선

1-prof.py

print('\n\n< Prof. code >')
print('-----------------------------------------')
num_links = 0
num_total_joints = 0
num_fixed_joints = 0
num_revolute_joints = 0
num_prismatic_joints = 0
processed_links = set()
processed_joints = set()
dof = 0

# Check each link and joint in the URDF file
for link in root.findall('.//link'): # tag
    link_name = link.get('name')                    # [!] None 체크 안함 => 안하면 런타임 시간 낭비
    if 'link' in link_name.lower():
        num_links += 1                              # [!] set을 사용하기 때문에 굳이 안에서 증감할 필요 없음 (my.py 참고)
        processed_links.add(link_name)

for joint in root.findall('.//joint'):
    parent_link = joint.find('parent').get('link')  # [!] None 체크 안함 => 프로그램 터질 수 있음
    child_link = joint.find('child').get('link')    # [!] None 체크 안함 => 프로그램 터질 수 있음
    
    joint_type = joint.get('type')                  # [!] None 체크 안함 (이건 안해도 괜춘할듯)

    if parent_link in processed_links and child_link in processed_links:
        joint_name = joint.get('name')
        if joint_name not in processed_joints:      # [!] set이기 때문에 중복 체크할 필요없음
            num_total_joints += 1                   # [!] set을 사용하기 때문에 굳이 증감할 필요 없음 (my.py 참고)
            processed_joints.add(joint_name)

            if joint_type == 'fixed':               # [!] if문 남발은 좋지 않음 타입이 여러개면 유지보수 힘듦 (my.py 참고)
                num_fixed_joints += 1
            elif joint_type == 'revolute':
                num_revolute_joints += 1
            elif joint_type == 'prismatic':
                num_prismatic_joints += 1

# Calculate DOF using Grubler's formula
m = 6
N = num_links
J = num_total_joints
sum_f_i = 0 * num_fixed_joints + 1 * num_revolute_joints + 1 * num_prismatic_joints
dof = m * (N - 1 - J) + sum_f_i

# Print the results
print("DOF:", dof)
print("Number of links with names containing 'link':", num_links)
print("Total number of joints connecting these links:", num_total_joints)
print("Number of fixed joints:", num_fixed_joints)
print("Number of revolute joints:", num_revolute_joints)
print("Number of prismatic joints:", num_prismatic_joints)

2-my.py

print('\n\n< My code >')
print('-----------------------------------------')
num_links = 0
num_total_joints = 0
num_fixed_joints = 0
num_revolute_joints = 0
num_prismatic_joints = 0
processed_links = set()
processed_joints = set()
dof = 0
joint_types_count = { 'fixed': 0, 'revolute': 0, 'prismatic': 0 }

# Check each link and joint in the URDF file
for link in root.findall('.//link'): # tag
    link_name = link.get('name')
    if link_name == None:
        continue
    if 'link' in link_name.lower():
        processed_links.add(link_name)

for joint in root.findall('.//joint'):
    parent = joint.find('parent')
    child = joint.find('child')
    if parent == None or child == None:
        continue
    parent_link = parent.get('link')
    child_link = child.get('link')

    joint_name = joint.get('name')
    joint_type = joint.get('type')
    if joint_name == None or joint_type == None:
        continue
    if parent_link in processed_links and child_link in processed_links:
        processed_joints.add(joint_name)
        joint_types_count[joint_type] = joint_types_count.get(joint_type, 0) + 1

num_links = len(processed_links)                        # [V] set 길이만 쟤면 됨
num_total_joints = len(processed_joints)     
num_fixed_joints = joint_types_count['fixed']           # [V] if문 남발 안하고 그냥 대입하면 끝
num_revolute_joints = joint_types_count['revolute']   
num_prismatic_joints = joint_types_count['prismatic']

# Calculate DOF using Grubler's formula
m = 6
N = num_links
J = num_total_joints
sum_f_i = 0 * num_fixed_joints + 1 * num_revolute_joints + 1 * num_prismatic_joints
dof = m * (N - 1 - J) + sum_f_i

# Print the results
print("DOF:", dof)
print("Number of links with names containing 'link':", num_links)
print("Total number of joints connecting these links:", num_total_joints)
print("Number of fixed joints:", num_fixed_joints)
print("Number of revolute joints:", num_revolute_joints)
print("Number of prismatic joints:", num_prismatic_joints)