How to find files with a string

[Brian Oney]

On Wed, 2019-01-09 at 08:29 -0800, anton.gridushko at gmail.com wrote:
> Hello everyone!
> 
> I need to find a file, that contains a string TeNum
> 
> I try to 
> 
> import os
> import sys
> def find_value(fname):
>     value = 0
>     with open(fname, encoding='cp866') as fn:
>         try:
>             for i in fn:
>                 if 'TeNam' in i:
>                     print(fname)
>         except IndexError:
>             pass
>     return {fname}
> def main():
>     dirname = ('H:\\1\\3')
>     os.chdir(dirname)
>     res = {}
>     for i in os.listdir(dirname):
>         res.update(find_value(i))
>     print('Filename is: ')
> if __name__ == "__main__":
>     main()
> 
> But there are mistakes like
> C:\Users\Anton\AppData\Local\Programs\Python\Python36-32\python.exe "C:/Users/Anton/PycharmProjects/Работа с файловой системой/Перебор файлов из папки.py"
> Traceback (most recent call last):
>   File "C:/Users/Anton/PycharmProjects/Работа с файловой системой/Перебор файлов из папки.py", line 21, in <module>
>     main()
>   File "C:/Users/Anton/PycharmProjects/Работа с файловой системой/Перебор файлов из папки.py", line 18, in main
>     res.update(find_value(i))
> ValueError: dictionary update sequence element #0 has length 35; 2 is required
> 
> Process finished with exit code 1
> 
> Could you help me to solve this thread?

the error message is somewhat clear. You need to add a key-value pair to
a dictionary. You may consider changing 'res' to a 'list'. You then need
to 'append'. 

Either way, 'find_value' will return the filename regardless of whether
the value is present or not. That should get you started.