問題描述:
在django的views.py視圖中定義視圖函數生成二維碼並返回給網頁,生成驗證碼過程中發生錯誤,如下:
TypeError: string argument expected, got 'bytes'
Traceback (most recent call last):
File "G:\anaconda\lib\site-packages\django\core\handlers\exception.py", line 34, in inner
response = get_response(request)
File "G:\anaconda\lib\site-packages\django\core\handlers\base.py", line 115, in _get_response
response = self.process_exception_by_middleware(e, request)
File "G:\anaconda\lib\site-packages\django\core\handlers\base.py", line 113, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "F:\django_lear\project2\myApp\views.py", line 73, in verifycode
im.save(buf, 'png')
File "G:\anaconda\lib\site-packages\PIL\Image.py", line 1930, in save
save_handler(self, fp, filename)
File "G:\anaconda\lib\site-packages\PIL\PngImagePlugin.py", line 731, in _save
fp.write(_MAGIC)
TypeError: string argument expected, got 'bytes'
[01/Jan/2020 14:32:25] "GET /myApp/verifycode/ HTTP/1.1" 500 77810
F:\django_lear\project2\myApp\views.py changed, reloading.
Watching for file changes with StatReloader
Performing system checks...
System check identified no issues (0 silenced).
January 01, 2020 - 14:35:57
Django version 2.2.6, using settings 'project2.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CTRL-BREAK.
Internal Server Error: /myApp/verifycode/
Traceback (most recent call last):
File "G:\anaconda\lib\site-packages\django\core\handlers\exception.py", line 34, in inner
response = get_response(request)
File "G:\anaconda\lib\site-packages\django\core\handlers\base.py", line 115, in _get_response
response = self.process_exception_by_middleware(e, request)
File "G:\anaconda\lib\site-packages\django\core\handlers\base.py", line 113, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "F:\django_lear\project2\myApp\views.py", line 73, in verifycode
im.save(buf, 'png')
File "G:\anaconda\lib\site-packages\PIL\Image.py", line 1930, in save
save_handler(self, fp, filename)
File "G:\anaconda\lib\site-packages\PIL\PngImagePlugin.py", line 731, in _save
fp.write(_MAGIC)
TypeError: string argument expected, got 'bytes'
[01/Jan/2020 14:36:06] "GET /myApp/verifycode/ HTTP/1.1" 500 77808
F:\django_lear\project2\myApp\views.py changed, reloading.
Watching for file changes with StatReloader
Performing system checks...
System check identified no issues (0 silenced).
January 01, 2020 - 14:36:41
Django version 2.2.6, using settings 'project2.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CTRL-BREAK.
Internal Server Error: /myApp/verifycode/
Traceback (most recent call last):
File "G:\anaconda\lib\site-packages\django\core\handlers\exception.py", line 34, in inner
response = get_response(request)
File "G:\anaconda\lib\site-packages\django\core\handlers\base.py", line 115, in _get_response
response = self.process_exception_by_middleware(e, request)
File "G:\anaconda\lib\site-packages\django\core\handlers\base.py", line 113, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "F:\django_lear\project2\myApp\views.py", line 73, in verifycode
im.save(buf, 'png')
File "G:\anaconda\lib\site-packages\PIL\Image.py", line 1930, in save
save_handler(self, fp, filename)
File "G:\anaconda\lib\site-packages\PIL\PngImagePlugin.py", line 731, in _save
fp.write(_MAGIC)
TypeError: string argument expected, got 'bytes'
生成驗證碼的代碼如下:
# 驗證碼
def verifycode(request):
# 引入繪圖模塊
from PIL import Image, ImageDraw, ImageFont
# 引入隨機函數模塊
import random
# 定義變量,用於畫面的背景色、寬、高
bgcolor = (random.randrange(20, 100), random.randrange(20, 100), 255)
width = 100
height = 25
# 創建畫面對象
im = Image.new('RGB', (width, height), bgcolor)
# 創建畫筆對象
draw = ImageDraw.Draw(im)
# 調用畫筆的point()函數繪製噪點
for i in range(0, 100):
xy = (random.randrange(0, width), random.randrange(0, height))
fill = (random.randrange(0, 255), 255, random.randrange(0, 255))
draw.point(xy, fill=fill)
# 定義驗證碼的備選值
str1 = 'ABCD123EFGHIJK456LMNOPQRS789TUVWXYZ0'
# 隨機選取4個值作爲驗證碼
rand_str = ''
for i in range(0, 4):
rand_str += str1[random.randrange(0, len(str1))]
# 構造字體對象
font = ImageFont.truetype(r'C:/windows/fonts/himalaya.ttf', 23)
# 構造字體顏色
fontcolor = (255, random.randrange(0, 255), random.randrange(0, 255))
# 繪製4個字
draw.text((5, 2), rand_str[0], font=font, fill=fontcolor)
draw.text((25, 2), rand_str[1], font=font, fill=fontcolor)
draw.text((50, 2), rand_str[2], font=font, fill=fontcolor)
draw.text((75, 2), rand_str[3], font=font, fill=fontcolor)
# 釋放畫筆
del draw
# 存入session,用於做進一步驗證
request.session['verifycode'] = rand_str
# 內存文件操作
import io
buf = io.StringIO()
# 將圖片保存在內存中,文件類型爲png
im.save(buf, 'png')
# 將內存中的圖片數據返回給客戶端,MIME類型爲圖片png
return HttpResponse(buf.getvalue(), 'image/png')
原因分析:
分析了很久沒沒找到原因,不過解決方案已經知道
解決方案:
用BytesIO替代StringIO即可解決問題
修改後代碼:
# 驗證碼
def verifycode(request):
# 引入繪圖模塊
from PIL import Image, ImageDraw, ImageFont
# 引入隨機函數模塊
import random
# 定義變量,用於畫面的背景色、寬、高
bgcolor = (random.randrange(20, 100), random.randrange(20, 100), 255)
width = 100
height = 25
# 創建畫面對象
im = Image.new('RGB', (width, height), bgcolor)
# 創建畫筆對象
draw = ImageDraw.Draw(im)
# 調用畫筆的point()函數繪製噪點
for i in range(0, 100):
xy = (random.randrange(0, width), random.randrange(0, height))
fill = (random.randrange(0, 255), 255, random.randrange(0, 255))
draw.point(xy, fill=fill)
# 定義驗證碼的備選值
str1 = 'ABCD123EFGHIJK456LMNOPQRS789TUVWXYZ0'
# 隨機選取4個值作爲驗證碼
rand_str = ''
for i in range(0, 4):
rand_str += str1[random.randrange(0, len(str1))]
# 構造字體對象
font = ImageFont.truetype(r'C:/windows/fonts/himalaya.ttf', 23)
# 構造字體顏色
fontcolor = (255, random.randrange(0, 255), random.randrange(0, 255))
# 繪製4個字
draw.text((5, 2), rand_str[0], font=font, fill=fontcolor)
draw.text((25, 2), rand_str[1], font=font, fill=fontcolor)
draw.text((50, 2), rand_str[2], font=font, fill=fontcolor)
draw.text((75, 2), rand_str[3], font=font, fill=fontcolor)
# 釋放畫筆
del draw
# 存入session,用於做進一步驗證
request.session['verifycode'] = rand_str
# 內存文件操作
import io
# buf = io.StringIO()
buf = io.BytesIO()
# 將圖片保存在內存中,文件類型爲png
im.save(buf, 'png')
# 將內存中的圖片數據返回給客戶端,MIME類型爲圖片png
return HttpResponse(buf.getvalue(), 'image/png')