使用python解三角函数时出错

问题描述

import math

number = input('Your Number: ')
ways = input('sin/cos/tan: ')

try:
    problem = ways(number)
    answer = math.problem
    print(f'The value of {ways} of {number} is: {problem}')

这是我的代码。

我想在python中使用数学模块来解决三角函数，但是每次运行它都会给我一个错误SyntaxError: unexpected EOF while parsing

解决方法

我尝试使用稍有不同的逻辑来测试输入的有效性，从而完全避免try except的问题。

此外，我使用了规范的解决方案在运行时将字符串映射到函数，即使用映射（在Python中为dict）。

这是我的解决方案，需要进行一些测试。

In [6]: import math 
   ...: trigs = {'sin':math.sin,'cos':math.cos,'tan':math.tan} 
   ...: while True: 
   ...:     try:
   ...:         number = input('Your Number: ')
   ...:         fnumber = float(number) 
   ...:         break 
   ...:     except ValueError: 
   ...:         print('You input a non-valid floating point number.\nPlease try again') 
   ...:         continue 
   ...: while True: 
   ...:     trig = input('sin/cos/tan: ') 
   ...:     if trig in trigs: break 
   ...:     print('You input a non-valid trig function.\nPlease try again') 
   ...:  
   ...: print(f'The value of {trig} of {number} is: {trigs[trig](fnumber)}')              
Your Number: ret
You input a non-valid floating point number.
Please try again
Your Number: 1.57
sin/cos/tan: ert
You input a non-valid trig function.
Please try again
sin/cos/tan: tan
The value of tan of 1.57 is: 1255.7655915007897

In [7]:                                                                                   

,

• 您应该有一个doubleSize块，甚至void doubleSize(char ***list,size_t *size) { size_t new_size = *size * 2; char **new_list = realloc(*list,new_size); if (!new_list) [ // Ignoring out-of-memory errors. } *list = new_list; *size = new_size; } 至少也要进行错误处理
• void doubleSize(char ***list,size_t *size) { *list = realloc(*list,( *size *= 2 )); } 实际上是功能，需要不同的输入

        try
        {
            SqlDataAdapter da = new SqlDataAdapter();
            sqlcon.Open();
            da.DeleteCommand = new SqlCommand("delete from tbl_registerStudent where rfidno = '" + rfidno + "'",sqlcon);
            da.DeleteCommand.ExecuteNonQuery();

            MessageBox.Show("" + rfidno);
            MessageBox.Show("Delete Successfull");
            sqlcon.Close();
            bindGrid();
        }
        catch (SqlException ex)
        {
            MessageBox.Show(ex.Message);
        }

,

1. 您需要添加except块来处理异常，以防代码中出现问题。

2. 您可以编写如下代码来完成所需的任务：

import math
number = input('Your Number: ')
ways = input('sin/cos/tan: ')

def math_func(num,type_func):
    func = {'sin': lambda: math.sin(num),'cos': lambda: math.cos(num),'tan': lambda: math.tan(num)}
    return func.get(type_func)()

try:
    answer = math_func(float(number),ways)
    print(f'The value of {ways} of {number} is: {answer}')
except:
    pass