teachers: edited imports, crud_teacher: added comments, models, class…

… Student: splitted f-string into two parts for better readability

src/app/api/api_v1/routes/teachers.py

@@ -1,11 +1,7 @@
 from fastapi import APIRouter, HTTPException, Body, status
-from db.models import Course, Student
-from crud import crud_user 
-from crud import crud_teacher, crud_student
-from crud.crud_course import get_course_by_id
-from crud.crud_course import course_exists, get_course_common_info, hide_course
-from crud.crud_section import create_sections, get_section_by_id, update_section_info, delete_section, validate_section
-from crud.crud_tag import create_tags, delete_tag_from_course, course_has_tag, check_tag_associations, delete_tag
+from db.models import Course, Student 
+from crud import crud_user, crud_teacher, crud_student
+from crud import crud_course, crud_section, crud_tag
 from schemas.teacher import TeacherEdit, TeacherCreate, TeacherSchema, TeacherApproveRequest
 from schemas.course import CourseCreate, CourseUpdate, CourseSectionsTags, CourseBase, CoursePendingRequests
 from schemas.section import SectionBase, SectionUpdate
@@ -139,7 +135,7 @@ async def create_course(
     - `HTTPException 401`: If the teacher is not authenticated.
 
     """
-    if await course_exists(db, course.title):
+    if await crud_course.course_exists(db, course.title):
         raise HTTPException(
             status_code=status.HTTP_409_CONFLICT,
             detail="Course with such title already exists",
@@ -171,7 +167,7 @@ async def update_course_home_page_picture(
     - `HTTPException 403`: If the teacher does not have access to the course.
     - `HTTPException 400`: If the file is corrupted or the media type is not supported.
     """
-    course = await get_course_common_info(db, course_id)
+    course = await crud_course.get_course_common_info(db, course_id)
     user_has_access, msg = crud_teacher.validate_course_access(course, teacher)
     if not user_has_access:
         raise HTTPException(
@@ -259,7 +255,7 @@ async def view_course_by_id(
             detail=f"Invalid sort_by parameter"
         )
 
-    course = await get_course_common_info(db, course_id)
+    course = await crud_course.get_course_common_info(db, course_id)
     user_has_access, msg = crud_teacher.validate_course_access(course, teacher)
     if not user_has_access:
         raise HTTPException(
@@ -295,7 +291,7 @@ async def approve_enrollment(db: dbDep,
     - `HTTPException 403`, if the teacher is not the owner of the course.
     """
 
-    course: Course = await get_course_by_id(db, course_id)
+    course: Course = await crud_course.get_course_by_id(db, course_id)
     if not course:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail='No such course')
 
@@ -331,7 +327,7 @@ async def update_course_info(
     - `HTTPException 401`, if the teacher is not authenticated.
     - `HTTPException 403`: If the authenticated teacher does not have permission to update the course.
     """
-    course = await get_course_common_info(db, course_id)
+    course = await crud_course.get_course_common_info(db, course_id)
     user_has_access, msg = crud_teacher.validate_course_access(course, teacher)
     if not user_has_access:
         raise HTTPException(
@@ -367,23 +363,23 @@ async def update_section(
     - `HTTPException 403`: If the authenticated teacher does not have permission to update the section.
     - `HTTPException 404`: If the section with the given ID does not exist or is not part of the specified course.
     """
-    course = await get_course_common_info(db, course_id)
+    course = await crud_course.get_course_common_info(db, course_id)
     user_has_access, msg = crud_teacher.validate_course_access(course, teacher)
     if not user_has_access:
         raise HTTPException(
             status_code=status.HTTP_403_FORBIDDEN,
             detail=msg
         )
 
-    section = await get_section_by_id(db, section_id)
-    valid_section, msg = validate_section(section, course_id)
+    section = await crud_section.get_section_by_id(db, section_id)
+    valid_section, msg = crud_section.validate_section(section, course_id)
     if not valid_section:
         raise HTTPException(
             status_code=status.HTTP_404_NOT_FOUND,
             detail=msg
         )
 
-    return await update_section_info(db, section, updates)
+    return await crud_section.update_section_info(db, section, updates)
 
 
 @router.post("/courses/{course_id}/sections", status_code=status.HTTP_201_CREATED, response_model=List[SectionBase])
@@ -408,15 +404,15 @@ async def add_sections(
     - `HTTPException 401`, if the teacher is not authenticated.
     - `HTTPException 403`: If the teacher does not have permission to add sections to the course.
     """
-    course = await get_course_common_info(db, course_id)
+    course = await crud_course.get_course_common_info(db, course_id)
     user_has_access, msg = crud_teacher.validate_course_access(course, teacher)
     if not user_has_access:
         raise HTTPException(
             status_code=status.HTTP_403_FORBIDDEN,
             detail=msg
         )
 
-    created_sections = await create_sections(db, sections, course_id)
+    created_sections = await crud_section.create_sections(db, sections, course_id)
     return created_sections
 
 
@@ -443,23 +439,23 @@ async def remove_section(
     - `HTTPException 403`: If the teacher does not have access to the course.
     - `HTTPException 404`: If the section is not found or does not belong to the specified course.
     """
-    course = await get_course_common_info(db, course_id)
+    course = await crud_course.get_course_common_info(db, course_id)
     user_has_access, msg = crud_teacher.validate_course_access(course, teacher)
     if not user_has_access:
         raise HTTPException(
             status_code=status.HTTP_403_FORBIDDEN,
             detail=msg
         )
 
-    section = await get_section_by_id(db, section_id)
-    valid_section, msg = validate_section(section, course_id)
+    section = await crud_section.get_section_by_id(db, section_id)
+    valid_section, msg = crud_section.validate_section(section, course_id)
     if not valid_section:
         raise HTTPException(
             status_code=status.HTTP_404_NOT_FOUND,
             detail=msg
         )
 
-    await delete_section(db, section)
+    await crud_section.delete_section(db, section)
     return
 
 
@@ -488,15 +484,15 @@ async def add_tags(
     - `HTTPException 401`: If the teacher is not authenticated.
     - `HTTPException 403`: If the teacher does not have permission to add tags to the course.
     """
-    course = await get_course_common_info(db, course_id)
+    course = await crud_course.get_course_common_info(db, course_id)
     user_has_access, msg = crud_teacher.validate_course_access(course, teacher)
     if not user_has_access:
         raise HTTPException(
             status_code=status.HTTP_403_FORBIDDEN,
             detail=msg
         )
 
-    created_tags = await create_tags(db, tags, course_id)
+    created_tags = await crud_tag.create_tags(db, tags, course_id)
     return created_tags
 
 
@@ -523,26 +519,26 @@ async def remove_tag(
     - `HTTPException 403`: If the teacher does not have access to the course.
     - `HTTPException 404`: If the tag is not associated with the course.
     """
-    course = await get_course_common_info(db, course_id)
+    course = await crud_course.get_course_common_info(db, course_id)
     user_has_access, msg = crud_teacher.validate_course_access(course, teacher)
     if not user_has_access:
         raise HTTPException(
             status_code=status.HTTP_403_FORBIDDEN,
             detail=msg
         )
 
-    course_tag = await course_has_tag(db, course_id, tag_id)
+    course_tag = await crud_tag.course_has_tag(db, course_id, tag_id)
     if not course_tag:
         raise HTTPException(
             status_code=status.HTTP_404_NOT_FOUND,
             detail=f"Tag with ID:{tag_id} not associated with course ID:{course_id}"
         )
 
-    await delete_tag_from_course(db, course_tag)
+    await crud_tag.delete_tag_from_course(db, course_tag)
 
-    tag_associations = await check_tag_associations(db, tag_id)
+    tag_associations = await crud_tag.check_tag_associations(db, tag_id)
     if tag_associations == 0:
-        await delete_tag(db, tag_id)
+        await crud_tag.delete_tag(db, tag_id)
 
     return
 
@@ -564,7 +560,7 @@ async def deactivate_course(db: dbDep, course_id: int, teacher: TeacherAuthDep):
     - `HTTPException 403`: If the teacher does not have access to the course.
     - `HTTPException 400`: If there are students enrolled in the course.
     """
-    course = await get_course_common_info(db, course_id)
+    course = await crud_course.get_course_common_info(db, course_id)
     user_has_access, msg = crud_teacher.validate_course_access(course, teacher)
     if not user_has_access:
         raise HTTPException(
@@ -577,7 +573,7 @@ async def deactivate_course(db: dbDep, course_id: int, teacher: TeacherAuthDep):
             status_code=status.HTTP_400_BAD_REQUEST,
             detail="Cannot deactivate a course with enrolled students"
         )
-    await hide_course(db, course)
+    await crud_course.hide_course(db, course)
     return
 
 

src/app/crud/crud_teacher.py

@@ -84,7 +84,7 @@ async def get_entire_course(db: Session, course: Course, teacher: Teacher, sort:
     if sort_by:
         sections_query = sections_query.order_by(
             getattr(Section, sort_by).desc() if sort and sort == 'desc' else getattr(Section, sort_by).asc()
-        )
+        ) # when sort_by is provided without sort, the sections are sorted in ascending order by default
 
     sections = sections_query.all()
     for section in sections:
@@ -182,8 +182,8 @@ async def calculate_student_progresses(db: Session, courses_with_students: List[
 
 async def get_courses_reports(db: Session, teacher: Teacher, min_progress: float, sort: str = None):
     courses_query = (
-        select(Course)
-        .options(joinedload(Course.students_enrolled))
+        select(Course)                                 #preventing the "N+1 problem"
+        .options(joinedload(Course.students_enrolled)) #all related students are fetched in the same query as the courses
         .where(Course.owner_id == teacher.teacher_id)
     )
 
@@ -192,8 +192,8 @@ async def get_courses_reports(db: Session, teacher: Teacher, min_progress: float
     elif sort == 'desc':
         courses_query = courses_query.order_by(Course.course_id.desc())
 
-    result = db.execute(courses_query)
-    courses_with_students = result.scalars().unique().all()
+    result = db.execute(courses_query) #result contains raw SQL rows
+    courses_with_students = result.scalars().all() # scalars() converts raw SQL rows into ORM objects(Course instances)
 
     student_progress_dict = await calculate_student_progresses(db, courses_with_students)
     courses_reports = generate_reports(courses_with_students, student_progress_dict, min_progress)

src/app/db/models.py

@@ -81,8 +81,8 @@ class Student(Base):
     courses_enrolled: Mapped[List['Course']] = relationship(
         'Course',
         secondary='students_courses',
-        primaryjoin=f"and_(Student.student_id == foreign(StudentCourse.student_id), StudentCourse.status == {
-            Status.active.value})",
+        primaryjoin=f"and_(Student.student_id == foreign(StudentCourse.student_id), "
+                    f"StudentCourse.status == {Status.active.value})",
         secondaryjoin="Course.course_id == foreign(StudentCourse.course_id)",
         back_populates="students_enrolled"
     )

src/app/tests/conftest.py

@@ -8,6 +8,7 @@
 from tests.api.api_v1.endpoints.student_test import dummy_student
 from tests.api.api_v1.endpoints.teacher_test import dummy_teacher
 from tests import dummies
+from typing import Generator
 
 
 @pytest.fixture
@@ -17,7 +18,7 @@ def client():
 
 
 @pytest.fixture(scope='function')
-def db() -> Session:
+def db() -> Generator:
     """
     This fixture returns a session connected to an in-memory SQLite db.
     It's intended for use in tests that require db access but should not