为什么这个变量没有在Python中定义？

Question

我一直在尝试制作一个 python 莫尔斯电码 t运行slator 并且过于复杂了，我想继续我正在为莫尔斯电码走的路t运行slator 但是我运行出问题了。

Traceback (most recent call last):
  File "python", line 114, in <module>
NameError: name 'firstletter' is not defined

我不明白为什么这个变量没有被定义。这是代码

wordinput = input("What do you want to convert")
word = str(wordinput.upper)

if word[0] == 'A':
    firstletter = ".-"
elif word[0] == "B":
    firstletter = "-..."
elif word[0] == 'C':
    firstletter = '-.-.'
elif word[0] == 'D':
    firstletter = '-..'
elif word[0] == 'E':
    firstletter = '.'
elif word[0] == 'F':
    firstletter = '..-.'
elif word[0] == 'G':
    firstletter = '--.'
elif word[0] == "H":
    firstletter = '....'
elif word[0] == "I":
    firstletter = '..'
elif word[0] == 'J':
    firstletter = ".."
elif word[0] == 'K':
    firstletter = '-.-'
elif word[0] == 'L':
    firstletter = '.-..'
elif word[0] == 'M':
    firstletter = '--'
elif word[0] == 'N':
    firstletter = '-.'
elif word[0] == 'O':
    firstletter = '---'
elif word[0] == 'P':
    firstletter = '.--.'
elif word[0] == 'Q':
    firstletter = '--.-'
elif word[0] == 'R':
    firstletter = '.-.'
elif word[0] == 'S':
    firstletter = '...'
elif word[0] == 'T':
    firstletter = '-'
elif word[0] == 'U':
    firstletter = '..-'
elif word[0] == 'V':
    firstletter = '...-'
elif word[0] == 'W':
    firstletter = '.--'
elif word[0] == 'X':
    firstletter = '-..-'
elif word[0] == 'Y':
    firstletter = '-.--'
elif word[0] == 'Z':
    firstletter = '--..'

if word[1] == 'A':
    secondletter = ".-"
elif word[1] == "B":
    secondletter = "-..."
elif word[1] == 'C':
    secondletter = '-.-.'
elif word[1] == 'D':
    secondletter = '-..'
elif word[1] == 'E':
    secondletter = '.'
elif word[1] == 'F':
    secondletter = '..-.'
elif word[1] == 'G':
    secondletter = '--.'
elif word[1] == "H":
    secondletter = '....'
elif word[1] == "I":
    secondletter = '..'
elif word[1] == 'J':
    secondletter = ".."
elif word[1] == 'K':
    secondletter = '-.-'
elif word[1] == 'L':
    secondletter = '.-..'
elif word[1] == 'M':
    secondletter = '--'
elif word[1] == 'N':
    secondletter = '-.'
elif word[1] == 'O':
    secondletter = '---'
elif word[1] == 'P':
    secondletter = '.--.'
elif word[1] == 'Q':
    secondletter = '--.-'
elif word[1] == 'R':
    secondletter = '.-.'
elif word[1] == 'S':
    secondletter = '...'
elif word[1] == 'T':
    secondletter = '-'
elif word[1] == 'U':
    secondletter = '..-'
elif word[1] == 'V':
    secondletter = '...-'
elif word[1] == 'W':
    secondletter = '.--'
elif word[1] == 'X':
    secondletter = '-..-'
elif word[1] == 'Y':
    secondletter = '-.--'
elif word[1] == 'Z':
    secondletter = '--..'





print(firstletter + secondletter)
import os
os.system("pause")

Answer 1

您的问题出在作业上：

word = str(wordinput.upper)

您未能调用函数upper；相反，您将函数描述符分配给 word。当您将该描述符转换为字符串时，word 的值为

"<built-in method upper of str object at 0x7f377ea143e8>"

因此，无论输入如何，您都在尝试转换 '<' 和 'b'；第一个在你的列表中没有覆盖，所以你的程序崩溃了。

更改调用例程的行：

word = str(wordinput.upper() )

进一步工作

The problem will still occur if the user enters any input other than pure letters.  Add a line before your long **if** to give a default value, whatever you'd like to see printed if the input isn't a letter.  I use a space here:

firstletter = ' '

改进

使用参考词典：

code = { 'A': ".-", 'B': "-...", etc.
       }

添加循环遍历字符串并转换单个字母：

for c in word:
    if c in code:
        morse_char = code[c]
    else:
        morse_char = ' '
    print(morse_char)

这能拯救你的手指肌肉吗？

Answer 2

我同意，我有两个建议给你第一的：在 if 语句上方定义第一个字母和第二个字母要么第二

使用for循环进行如下转换

wordinput = input("")
word = str(wordinput.upper)

for letter in range(0,len(word)+1):
    if word[letter] == A:
        convertedword.append(.-)
...
...
...

为什么这个变量没有在Python中定义？

Why is this variable not defined in Python?

python

morse-code