Python Turtle光标不移动求助：学生成绩柱状图无法绘制

Hey there, let's troubleshoot why your turtle bar chart isn't rendering even though the window pops up. After going through your code, I found several key issues that are preventing the drawing from happening—let's break them down and fix them step by step.

Key Issues in Your Code #

• Incorrect total marks collection in getTotalMarks:
  You were calculating the sum of all students' marks into a single integer, then trying to loop over range(total) which doesn't make sense for individual student bars. We need to collect each student's total score into a list instead.
• Turtle namespace conflict:
  You overwrote the turtle module reference with turtle = turtle.Turtle()—this breaks access to module-level functions later. Use a different variable name like t for the Turtle object.
• Truncated code in displayAStudentsDetail:
  The line sum(studentM is incomplete; it should be sum(studentMarkList) to calculate the student's total score.
• Missing program entry point:
  Your original code didn't call the menu() function to start the program, so it wouldn't run at all!

Corrected Full Code #

def menu():
    allStudentsMarks = {}
    while True:
        userinput = input("Enter 1 to store student details \n"+
                         "Enter 2 to display student report \n"+
                         "Enter 3 to exit \n")
        if userinput == "1":
            enterMarks(allStudentsMarks)
        elif userinput == "2":
            displayReports(allStudentsMarks)
        elif userinput == "3":
            print("You have left the program. Thank you.")
            break

def enterMarks(allStudentsMarks):
    studentName = input("Please enter the student's name: ")
    while True:
        DFMarks = input("Please enter the marks from 0-20: ")
        DFMarks = float(DFMarks)
        if DFMarks >= 0 and DFMarks <= 20:
            break
    while True:
        ProjectMarks = input("Please enter the marks from 0-30: ")
        ProjectMarks = float(ProjectMarks)
        if ProjectMarks >= 0 and ProjectMarks <= 30:
            break
    while True:
        FinalMarks = input("Please enter the marks from 0-50: ")
        FinalMarks = float(FinalMarks)
        if FinalMarks >= 0 and FinalMarks <= 50:
            break
    marksList = [DFMarks, ProjectMarks, FinalMarks]
    allStudentsMarks[studentName] = marksList

def getBelowAvgDFMarks(studentDetails):
    marks = list(studentDetails.values())
    dfTot = 0
    dfLen = 0
    for marksList in marks:
        dfTot += marksList[0]
        dfLen += 1
    dfAvg = dfTot / dfLen
    print("Displaying the student(s) whose DF marks are below the average of", dfAvg)
    belowAvgDF = {}
    for student in studentDetails:
        if studentDetails[student][0] < dfAvg:
            belowAvgDF[student] = studentDetails[student][0]
    print(belowAvgDF)
    return

def getBelowAvgProjectMarks(studentDetails):
    marks = list(studentDetails.values())
    projectTot = 0
    projectLen = 0
    for marksList in marks:
        projectTot = projectTot + marksList[1]
        projectLen = projectLen + 1
    projectAvg = projectTot / projectLen
    print("Displaying the student(s) whose project marks are below the average of", projectAvg)
    belowAvgProject = {}
    for student in studentDetails:
        if studentDetails[student][1] < projectAvg:
            belowAvgProject[student] = studentDetails[student][1]
    print(belowAvgProject)
    return

def getBelowAvgFinalExamMarks(studentDetails):
    marks = list(studentDetails.values())
    finalTot = 0
    finalLen = 0
    for marksList in marks:
        finalTot = finalTot + marksList[2]
        finalLen = finalLen + 1
    finalAvg = finalTot / finalLen
    print("Displaying the student(s) whose final marks are below the average of", finalAvg)
    belowAvgFinal = {}
    for student in studentDetails:
        if studentDetails[student][2] < finalAvg:
            belowAvgFinal[student] = studentDetails[student][2]
    print(belowAvgFinal)
    return

def getBelowAvgOverallMarks(studentDetails):
    marks = list(studentDetails.values())
    overall = 0
    overallLen = len(marks)
    for marksList in marks:
        for num in marksList:
            overall += num
    overallAvg = overall / overallLen
    print("Overall average marks:", overallAvg)
    print("Displaying the student(s) whose overall marks are below the average of", overallAvg)
    belowAvgOverall = {}
    for student in studentDetails:
        if sum(studentDetails[student]) < overallAvg:
            belowAvgOverall[student] = sum(studentDetails[student])
    print(belowAvgOverall)
    return

def getTotalMarks(studentDetails):
    # Collect each student's total score into a list
    student_totals = [sum(marks) for marks in studentDetails.values()]
    print("All students' total marks:", student_totals)
    
    import turtle
    wn = turtle.Screen()
    # Use a different variable name to avoid overwriting the module
    t = turtle.Turtle()
    t.color("blue", "lightblue")
    t.penup()
    # Move to a starting position so bars aren't off-screen
    t.goto(-200, -100)
    t.pendown()
    
    # Loop through each student's total to draw bars
    for total in student_totals:
        t.begin_fill()
        # Draw a rectangle: width 20, height equal to total marks
        t.forward(20)
        t.left(90)
        t.forward(total)
        t.left(90)
        t.forward(20)
        t.left(90)
        t.forward(total)
        t.left(90)
        t.end_fill()
        # Move to next bar position with spacing
        t.penup()
        t.forward(30)
        t.pendown()
    
    wn.exitonclick()

def displayReports(allStudentsDetails):
    userinput = input("Enter 1 to get the average DF report marks \n"+
                     "Enter 2 to get the average project report marks \n"+
                     "Enter 3 to get the average final exam marks \n"+
                     "Enter 4 to get the overall marks \n"+
                     "Enter 5 to get the selected student marks \n"+
                     "Enter 6 to get the bar chart of the total marks \n")
    if userinput == "1":
        getBelowAvgDFMarks(allStudentsDetails)
    elif userinput == "2":
        getBelowAvgProjectMarks(allStudentsDetails)
    elif userinput == "3":
        getBelowAvgFinalExamMarks(allStudentsDetails)
    elif userinput == "4":
        getBelowAvgOverallMarks(allStudentsDetails)
    elif userinput == "5":
        displaySelectedStudentsMarks(allStudentsDetails)
    elif userinput == "6":
        getTotalMarks(allStudentsDetails)
    return

def displaySelectedStudentsMarks(selectedStudentsDetails):
    for studentNameKey in selectedStudentsDetails:
        displayAStudentsDetail(studentNameKey, selectedStudentsDetails[studentNameKey])

def displayAStudentsDetail(studentName, studentMarkList):
    total = sum(studentMarkList)
    print("Student name: ", studentName)
    print(f"DF marks: {studentMarkList[0]}\tProject marks: {studentMarkList[1]}\tFinal exam: {studentMarkList[2]}\tTotal marks: {total}")

# Start the program by calling the menu function
menu()

What Changed & Why #

1. Fixed getTotalMarks:
   • Now collects each student's total score into a list, so we can loop through and draw an individual bar for each student.
   • Added a starting position for the turtle to ensure bars are visible on the screen (no more off-screen drawing!).
   • Added spacing between bars for better readability.
2. Resolved Turtle Namespace Conflict:
   • Renamed the Turtle object to t instead of turtle, so we don't overwrite the module reference.
3. Fixed Truncated Code:
   • Completed the total score calculation in displayAStudentsDetail for cleaner output.
4. Added Program Entry Point:
   • Added menu() at the end to launch the program—your original code was missing this critical step!

Now when you select option 6 from the report menu, the turtle window should draw a bar for each student's total score. If bars are too tall or short, you can adjust the scaling (e.g., multiply total by 2 in t.forward(total) to make bars taller).

内容的提问来源于stack exchange，提问作者Kelvin Gunawan