python 遇到錯誤處理（Python常見異常錯誤）

2023-04-16 20:17:28

python 遇到錯誤處理?1. 忘記寫冒號在 if、elif、else、for、while、def語句後面忘記添加 :age = 42if age == 42 print('Hello!')，接下來我們就來聊聊關於python 遇到錯誤處理?以下內容大家不妨參考一二希望能幫到您!

python 遇到錯誤處理

1. 忘記寫冒號

在 if、elif、else、for、while、def語句後面忘記添加 :age = 42if age == 42 print('Hello!')

age = 42 if age == 42 print ( 'Hello!' ) File "" , line 2 if age == 42 ^ SyntaxError : invalid syntax

2. 誤用 =

= 是賦值操作，而判斷兩個值是否相等是 ==

gender = '男' if gender = '男' : print ( 'Man' ) File "" , line 2 if gender = '男' : ^ SyntaxError : invalid syntax

3. 錯誤的縮進

Python用縮進區分代碼塊，常見的錯誤用法：

print('Hello!') print('Howdy!') File "", line 2 print('Howdy!') ^ IndentationError: unexpected indent num = 25 if num == 25: print('Hello!') File "", line 3 print('Hello!') ^ IndentationError: expected an indented block

4. 變量沒有定義

if city in ['New York', 'Bei Jing', 'Tokyo']: print('This is a mega city') --------------------------------------------------------------------------- NameError Traceback (most recent call last) in ----> 1 if city in ['New York', 'Bei Jing', 'Tokyo']: 2 print('This is a mega city') NameError: name 'city' is not defined

5. 中英文輸入法導致的錯誤

if 5>3： print('5比3大') File "", line 1 if 5>3： ^ SyntaxError: invalid character in identifier if 5>3: print('5比3大') File "", line 2 print('5比3大') ^ SyntaxError: invalid character in identifier spam = [1, 2，3] File "", line 1 spam = [1, 2，3] ^ SyntaxError: invalid character in identifier if 5>3: print('5比3大『) File "", line 2 print('5比3大『) ^ SyntaxError: EOL while scanning string literal

6. 不同數據類型的拼接

字符串/列表/元組 支持拼接

字典/集合不支持拼接

'I have ' 12 ' eggs. '#'I have {} eggs.'.format(12) --------------------------------------------------------------------------- TypeError Traceback (most recent call last) in ----> 1 'I have ' 12 ' eggs.' TypeError: can only concatenate str (not "int") to str ['a', 'b', 'c'] 'def' --------------------------------------------------------------------------- TypeError Traceback (most recent call last) in ----> 1 ['a', 'b', 'c'] 'def' TypeError: can only concatenate list (not "str") to list ('a', 'b', 'c') ['a', 'b', 'c'] --------------------------------------------------------------------------- TypeError Traceback (most recent call last) in ----> 1 ('a', 'b', 'c') ['a', 'b', 'c'] TypeError: can only concatenate tuple (not "list") to tuple set(['a', 'b', 'c']) set(['d', 'e']) --------------------------------------------------------------------------- TypeError Traceback (most recent call last) in ----> 1 set(['a', 'b', 'c']) set(['d', 'e']) TypeError: unsupported operand type(s) for : 'set' and 'set' grades1 = {'Mary':99, 'Henry':77} grades2 = {'David':88, 'Unique':89} grades1 grades2 --------------------------------------------------------------------------- TypeError Traceback (most recent call last) in 2 grades2 = {'David':88, 'Unique':89} 3 ----> 4 grades1 grades2 TypeError: unsupported operand type(s) for : 'dict' and 'dict'

7. 索引位置問題

spam = ['cat', 'dog', 'mouse']print(spam[5]) --------------------------------------------------------------------------- IndexError Traceback (most recent call last) in 1 spam = ['cat', 'dog', 'mouse']----> 2 print(spam[5]) IndexError: list index out of range

8. 使用字典中不存在的鍵

在字典對象中訪問 key 可以使用 []，

但是如果該 key 不存在，就會導致：KeyError: 'zebra'

spam = {'cat': 'Zophie', 'dog': 'Basil', 'mouse': 'Whiskers'} print(spam['zebra']) --------------------------------------------------------------------------- KeyError Traceback (most recent call last) in 3 'mouse': 'Whiskers'} 4 ----> 5 print(spam['zebra']) KeyError: 'zebra'

為了避免這種情況，可以使用 get 方法

spam = {'cat': 'Zophie', 'dog': 'Basil', 'mouse': 'Whiskers'} print(spam.get('zebra')) None

key 不存在時，get 默認返回 None

9. 忘了括號

當函數中傳入的是函數或者方法時，容易漏寫括號

spam = {'cat': 'Zophie', 'dog': 'Basil', 'mouse': 'Whiskers'} print(spam.get('zebra') File "", line 5 print(spam.get('zebra') ^ SyntaxError: unexpected EOF while parsing

10. 漏傳參數

def diyadd(x, y, z): return x y zdiyadd(1, 2) --------------------------------------------------------------------------- TypeError Traceback (most recent call last) in 2 return x y z 3 ----> 4 diyadd(1, 2) TypeError: diyadd missing 1 required positional argument: 'z'

11. 缺失依賴庫

電腦中沒有相關的庫

12. 使用了python中的關鍵詞

如try、except、def、class、object、None、True、False等

try = 5print(try) File " ", line 1 try = 5 ^ SyntaxError: invalid syntax def = 6 print(6) File "", line 1 def = 6 ^ SyntaxError: invalid syntax

13. 文件編碼問題

import pandas as pd df = pd.read_csv('data/twitter情感分析數據集.csv') df.head

嘗試encoding編碼參數傳入utf-8、gbk

df = pd.read_csv('data/twitter情感分析數據集.csv', encoding='utf-8') df.head

都報錯說明編碼不是utf-8和gbk，而是不常見都編碼，這裡我們需要傳入正確都encoding，才能讓程序運行。

python有個chardet庫，專門用來偵測編碼。

import chardet binary_data = open('data/twitter情感分析數據集.csv', 'rb').read chardet.detect(binary_data) {'encoding': 'Windows-1252', 'confidence': 0.7291192008535122, 'language': ''}