Python進度條ValueError：值超出范圍

Question

我的進度條達到100％，然后拋出錯誤

from progressbar import Percentage, ProgressBar,Bar,ETA

pbar = ProgressBar(widgets=[Bar('=', '[', ']'), ' ',
                                            Percentage(), ' ',
                                            ETA()]).start()
            for i,row in enumerate(cursor):

               '''
                do some work here

               ''' 

                pbar.update(i)

這就是我得到的

Traceback (most recent call last):=========================] 100% ETA:  0:00:00
  File "X:\src\dbtest\PymssqlCheck.py", line 27, in <module>
    fiddler.getRows(condetails, dbdetails, 'compliance', 'doctable', '*', '1000')
  File "X:\src\utilities\fiddler.py", line 45, in getRows
    pbar.update(i)
  File "X:\Anaconda2\lib\site-packages\progressbar\__init__.py", line 271, in update
    raise ValueError('Value out of range')
ValueError: Value out of range

為什么它達到100％然后失敗？ 我在用

https://github.com/niltonvolpato/python-progressbar

我甚至試過了

 i=0                                
            for row in cursor:

                ''' do some work here ''' 

                if i < numrows:
                    pbar.update(i)
                    i=i+1

但我仍然得到同樣的錯誤

編輯

我試過Tomasz Jakub Rup回答

pbar = ProgressBar(widgets=[Bar('=', '[', ']'), ' ',
                                        Percentage(), ' ',
                                        ETA()])
for row in pbar(cursor):
    ''' do some work here ''' 

我明白了

File "X:\fiddler.py", line 41, in getRows
    for row in pbar(cursor):
  File "X:\Anaconda2\lib\site-packages\progressbar\__init__.py", line 180, in __next__
    if self.start_time is None: self.start()
  File "X:\Anaconda2\lib\site-packages\progressbar\__init__.py", line 311, in start
    self.update(0)
  File "X:\Anaconda2\lib\site-packages\progressbar\__init__.py", line 283, in update
    self.fd.write(self._format_line() + '\r')
  File "X:\Anaconda2\lib\site-packages\progressbar\__init__.py", line 243, in _format_line
    widgets = ''.join(self._format_widgets())
  File "X:\Anaconda2\lib\site-packages\progressbar\__init__.py", line 223, in _format_widgets
    widget = format_updatable(widget, self)
  File "X:\Anaconda2\lib\site-packages\progressbar\widgets.py", line 38, in format_updatable
    if hasattr(updatable, 'update'): return updatable.update(pbar)
  File "X:\Anaconda2\lib\site-packages\progressbar\widgets.py", line 184, in update
    return '%3d%%' % pbar.percentage()
  File "X:\Anaconda2\lib\site-packages\progressbar\__init__.py", line 208, in percentage
    return self.currval * 100.0 / self.maxval
TypeError: unsupported operand type(s) for /: 'float' and 'classobj'

任何想法為什么？

Answer 1

因為進度條默認為100。 如果有N步，則應指定maxval=N

例如：

from progressbar import Percentage, ProgressBar,Bar,ETA

N = 300

pbar = ProgressBar(widgets=[Bar('=', '[', ']'), ' ', Percentage(), ' ', ETA()],
                   maxval=N).start()

for i in range(N+1):
    pbar.update(i)

Answer 2

大衛和托馬斯，你們倆都非常接近。 有效的解決方案是

pbar = ProgressBar(widgets=[Bar('>', '[', ']'), ' ',
                                            Percentage(), ' ',
                                            ETA()],maxval=someMaxValue)
            for row in pbar(cursor):
                ''' do some work '''

Answer 3

progress = ProgressBar（maxval = my.objects.count（）或None）.start（）為我固定

參考： https ： //github.com/niltonvolpato/python-progressbar/issues/36

Answer 4

嘗試：

pbar = ProgressBar(widgets=[Bar('=', '[', ']'), ' ',
                                        Percentage(), ' ',
                                        ETA()])
for row in pbar(cursor.fetchall()):
    ''' do some work here ''' 

在這種情況下，您不需要更新pbar ，也不需要啟動和完成pbar 。