Nested list: TypeError: expected string or bytes-like object

Question

我有一个嵌套列表，我想在其中进行一些字符串操作。但是，我收到了此类错误。有谁知道这是什么意思？

def format_Well_Data(welldata):
       cor_welldata=[]
       for Well in welldata:
            pattern = re.search(r'\d{2}\/',Well)
            ii = pattern.start()
            well2 = Well[0:ii] + '  ' + Well[ii:]
            a=cor_welldata.append(well2)
        print(a)
 format_Well_Data([['AMV-10st102/13/19 4  954  3,968  '],
                  ['AMV-0201/24/19 6  3,078  1,303 ' ]])

The code should add 2 space at the start of the date(mm/dd/yy):
[['AMV-10st1  02/13/19 4  954  3,968  '],['AMV-02  01/24/19 6  3,078  1,303 ' ]]

However, i get this huge error message:
C:\Users\gogut\AppData\Local\Continuum\anaconda3\envs\PTT\python.exe C:/APPL/DPI/PDF_reader/regextest_loop.py
Traceback (most recent call last):
  File "C:/APPL/DPI/PDF_reader/regextest_loop.py", line 14, in <module>
    ['AMV-0201/24/19 6  3,078  1,303 ' ]])
  File "C:/APPL/DPI/PDF_reader/regextest_loop.py", line 6, in format_Well_Data
    pattern = re.search(r'\d{2}\/',Well)
  File "C:\Users\gogut\AppData\Local\Continuum\anaconda3\envs\PTT\lib\re.py", line 182, in search
    return _compile(pattern, flags).search(string)
TypeError: expected string or bytes-like object

Answer 1

所以有两件事。

首先是 re.search 需要一个字符串，目前您提供一个列表。如果只有一个元素，为什么需要包含一个列表？如果有更多只是压扁它们？

第二个 .append 方法不 return 附加列表，它 returns None。这是一个就地操作，所以只打印列表。

import re
def format_Well_Data(welldata):
    cor_welldata=[]
    for Well in welldata:
        pattern = re.search(r'\d{2}\/', Well)
        ii = pattern.start()
        well2 = Well[0:ii] + '  ' + Well[ii:]
        cor_welldata.append(well2)
    print(cor_welldata)

format_Well_Data(['AMV-10st102/13/19 4  954  3,968  ',
                  'AMV-0201/24/19 6  3,078  1,303 ' ])

输出：

['AMV-10st1  02/13/19 4  954  3,968  ', 'AMV-02  01/24/19 6  3,078  1,303 ']

Answer 2

您需要 return 来自函数的数据，加上在您的输入中，您已将数据保存在列表的列表中。以下是不修改输入数据的解决方案

import re
def format_Well_Data(welldata):
    cor_welldata=[]
    for Well in welldata:
           for wells in Well:
               pattern = re.search(r'\d{2}\/',wells)
               ii = pattern.start()
               well2 = wells[0:ii] + '  ' + wells[ii:]
               cor_welldata.append(well2)
    print(cor_welldata)
    return cor_welldata

format_Well_Data([['AMV-10st102/13/19 4  954  3,968  '],
                  ['AMV-0201/24/19 6  3,078  1,303 '] ])

否则，如果您不修改当前代码，则可以将输入数据修改为

来自

[['AMV-10st102/13/19 4 954 3,968 '],['AMV-0201/24/19 6 3,078 1,303 '] ]

到['AMV-10st102/13/19 4 954 3,968 ','AMV-0201/24/19 6 3,078 1,303 ' ]

这里是小改进代码

import re
def format_Well_Data(welldata):
    cor_welldata=[]
    for Well in welldata:
        patt = re.findall(r'\d\d/\d\d/\d\d',Well)
        str1 = Well.replace(patt[0], ' {}'.format(patt[0]))
        cor_welldata.append(str1)
    return cor_welldata

format_Well_Data(['AMV-10st102/13/19 4  954  3,968  ',
                  'AMV-0201/24/19 6  3,078  1,303 ' ])
"""
output

 ['AMV-10st1 02/13/19 4  954  3,968  ', 'AMV-02 01/24/19 6  3,078  1,303 ']

 """

Nested list: TypeError: expected string or bytes-like object

Nested list: TypeError: expected string or bytes-like object

python

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list

nested-lists