我在 Eclipse 编译器中遇到缩进错误，有人知道为什么吗？

Question

我的 Eclipse 编译器出现缩进错误，我已在下面的特定行上标记了错误所在的位置。有人对修复有任何想法吗？这是学校的一项作业，我不知道如何解决，我完全完全不知所措。我会很感激任何人的提示。 “编写一个基于 GUI 的程序来模拟一个简单的袖珍计算器。GUI 显示一个用于输出的输入字段（我建议将其设为只读字段）。它应该为用户提供从 0 到 9 和 7 的 10 个数字按钮+、-、*、/、C（C 用于清除显示）、.（小数点）和 =.= 的功能键用于计算正确答案。如果出现除以零之类的错误，则输入字段应显示 ERR 或错误。输入字段中的值将构建一个字符串，该字符串将转换为浮点数进行计算。”这是我必须完成的任务。

from tkinter import *
from tkinter import font as tkFont # for convenience

expression = ""
# functions
def input_number(number, equation):

    global expression

# concatenation of string
    expression = expression + str(number)
    equation.set(expression)


def clear_input_field(equation):
    global expression
    expression = ""


# setting empty string in the input field
    equation.set("Enter the expression")



def evaluate(equation):
    global expression


# trying to evaluate the expression
    try:
        result = str(eval(expression))
        equation.set(result)
        expression = ""
    except:
        equation.set("Error: Divide by zero")
        expression = ""

def main():
    # creating main window
    tk = Tk()
# setting the title
    tk.title("Calculator")
# seting the size of window
    tk.geometry("570x500")
# varible class instantiation
    equation = StringVar()
# input field for the expression
    input_field = Entry(tk, textvariable=equation)
    input_field.place(height=100)

    input_field.grid(columnspan=4, ipadx=200, ipady=10)

    equation.set("Enter the expression")

    myFont = tkFont.Font(family='Helvetica', size=12, weight='bold')
    input_field['font']=myFont

# creating buttons and placing them at respective positions
        _1 = Button(tk, text='1', fg='black', bg='red', bd=2, command=lambda: input_number(1, equation), height=5, width=10) #I'm getting an error on this line
        _1['font'] = myFont
        _1.grid(row=2, column=0)
        _2 = Button(tk, text='2', fg='black', bg='red', bd=2, command=lambda: input_number(2, equation), height=5, width=10)
        _2.grid(row=2, column=1)
        _3 = Button(tk, text='3', fg='black', bg='red', bd=2, command=lambda: input_number(3, equation), height=5, width=10)
        _3.grid(row=2, column=2)
        _4 = Button(tk, text='4', fg='black', bg='red', bd=2, command=lambda: input_number(4, equation), height=5, width=10)
        _4.grid(row=3, column=0)
        _5 = Button(tk, text='5', fg='black', bg='red', bd=2, command=lambda: input_number(5, equation), height=5, width=10)
        _5.grid(row=3, column=1)
        _6 = Button(tk, text='6', fg='black', bg='red', bd=2, command=lambda: input_number(6, equation), height=5, width=10)
        _6.grid(row=3, column=2)
        _7 = Button(tk, text='7', fg='black', bg='red', bd=2, command=lambda: input_number(7, equation), height=5, width=10)
        _7.grid(row=4, column=0)
        _8 = Button(tk, text='8', fg='black', bg='red', bd=2, command=lambda: input_number(8, equation), height=5, width=10)
        _8.grid(row=4, column=1)
        _9 = Button(tk, text='9', fg='black', bg='red', bd=2, command=lambda: input_number(9, equation), height=5, width=10)
        _9.grid(row=4, column=2)
        _0 = Button(tk, text='0', fg='black', bg='red', bd=2, command=lambda: input_number(0, equation), height=5, width=10)
        _0.grid(row=5, column=0)
        plus = Button(tk, text='+', fg='black', bg='red', bd=2, command=lambda: input_number('+', equation), height=5, width=10)
        plus.grid(row=2, column=3)
        minus = Button(tk, text='-', fg='black', bg='red', bd=2, command=lambda: input_number('-', equation), height=5, width=10)
        minus.grid(row=3, column=3)
        multiply = Button(tk, text='*', fg='black', bg='red', bd=2, command=lambda: input_number('*', equation), height=5, width=10)
        multiply.grid(row=4, column=3)
        divide = Button(tk, text='/', fg='black', bg='red', bd=2, command=lambda: input_number('/', equation), height=5, width=10)
        divide.grid(row=5, column=3)
        equal = Button(tk, text='=', fg='black', bg='red', bd=2, command=lambda: evaluate(equation), height=5, width=10)
        equal.grid(row=5, column=2)
        _1['font'] = myFont
        _2['font'] = myFont
        _3['font'] = myFont
        _4['font'] = myFont
        _5['font'] = myFont
        _6['font'] = myFont
        _7['font'] = myFont
        _8['font'] = myFont
        _9['font'] = myFont
        _0['font'] = myFont

    plus['font'] = myFont
    minus['font'] = myFont
    multiply['font'] = myFont
    divide['font'] = myFont
    equal['font'] = myFont
    clear = Button(tk, text='Clear', fg='black', bg='red', bd=2, command=lambda: clear_input_field(equation), height=5, width=10)
    clear.grid(row=5, column=1)
    clear['font']=myFont
# showing the GUI continue
    tk.mainloop()

if __name__ == '__main__':
main()```

Answer 1

您突出显示的行和以下行通过额外的步骤缩进 - 确保它们与上面的行对齐，因为它们不在另一个块内（例如函数或 if 语句）