Find specific string and output the whole line Python

Question

I am having the following input txt file:

17,21.01.2019,0,0,0,0,E,75,meter tamper alarm
132,22.01.2019,64,296,225,996,A,,
150,23.01.2019,63,353,351,805,A,,
213,24.01.2019,64,245,244,970,A,,
201,25.01.2019,86,297,364,943,A,,
56,26.01.2019,73,678,678,1437,A,,
201,27.01.2019,83,654,517,1212,A,,
117,28.01.2019,58,390,202,816,A,,
69,29.01.2019,89,354,282,961,C,,
123,30.01.2019,53,267,206,852,A,,

Need to make a python program that can parse through the file. I need to find all the lines not containing A or C and output those lines in a new file. I'm completely stuck after trying several regex :( can you help me ?

Read the file line by line, split it by commas and check if any of the elements is A or C. — Guy
– Guy, Commented Feb 17, 2020 at 6:38
Can't you just use if "string" in lineString: and check if it does not contain both "A" and "C" — Raildex
– Raildex, Commented Feb 17, 2020 at 6:50

Vishnudev Krishnadas · Accepted Answer · 2020-02-17 06:52:09Z

3

Try

with open('filename') as f:
    for line in f.readlines():
        if 'A' not in line or 'C' not in line:
            print(line)

OR Better, as your file content seems to resemble a csv(Comma Seperated Values) format, use pandas for better manipulations

Read the file

import pandas as pd
df = pd.read_csv('filename', header=None, sep=',')

     0           1   2    3    4     5  6     7                   8
0   17  21.01.2019   0    0    0     0  E  75.0  meter tamper alarm
1  132  22.01.2019  64  296  225   996  A   NaN                 NaN
2  150  23.01.2019  63  353  351   805  A   NaN                 NaN
3  213  24.01.2019  64  245  244   970  A   NaN                 NaN
4  201  25.01.2019  86  297  364   943  A   NaN                 NaN
5   56  26.01.2019  73  678  678  1437  A   NaN                 NaN
6  201  27.01.2019  83  654  517  1212  A   NaN                 NaN
7  117  28.01.2019  58  390  202   816  A   NaN                 NaN
8   69  29.01.2019  89  354  282   961  C   NaN                 NaN
9  123  30.01.2019  53  267  206   852  A   NaN                 NaN

Output

print(df[~df[6].str.contains('A|C', regex=True)])

    0           1  2  3  4  5  6     7                   8
0  17  21.01.2019  0  0  0  0  E  75.0  meter tamper alarm

edited Feb 17, 2020 at 6:52

answered Feb 17, 2020 at 6:39

Vishnudev Krishnadas

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1 Comment

Vishnudev Krishnadas Over a year ago

Updated. Please check @Guy

gbruenjes · Accepted Answer · 2020-02-17 06:39:09Z

0

Try:

with open(r'file.txt', 'r') as f:
    for line in f:
        if 'A' not in line or 'C' not in line:
            print(line)

answered Feb 17, 2020 at 6:39

gbruenjes

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3 Comments

Sakrayaami S Over a year ago

You are simply great, thank you for those fast responses! Another small question is there a way also to exclude any negative numbers?

gbruenjes Over a year ago

@SakrayaamiS not as simple as it is right now. like this you are only comparing strings. you could search for '-' not in line. but for the I would recommend to use pandas like @Vishnudev did

gbruenjes Over a year ago

you could split at every , and try to cast it to float and check if its negative

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