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Extract Invalid Data From Dataframe to a File (.txt)

First time post here and new to python. My program should take a json file and convert it to csv. I have to check each field for validity. For a record that does not have all valid fields, I need to output those records to file. My question is, how would I take the a invalid data entry and save it to a text file? Currently, the program can check for validity but I do not know how to extract the data that is invalid.
import numpy as np
import pandas as pd
import logging
import re as regex
from validate_email import validate_email
# Variables for characters
passRegex = r"^(?!.*\s)(?=.*[A-Z])(?=.*[a-z])(?=.*\d).{8,50}$"
nameRegex = r"^[a-zA-Z0-9\s\-]{2,80}$"
# Read in json file to dataframe df variable
# Read in data as a string
df = pd.read_json('j2.json', dtype={'string'})
# Find nan values and replace it with string
#df = df.replace(np.nan, 'Error.log', regex=True)
# Data validation check for columns
df['accountValid'] = df['account'].str.contains(nameRegex, regex=True)
df['userNameValid'] = df['userName'].str.contains(nameRegex, regex=True)
df['valid_email'] = df['email'].apply(lambda x: validate_email(x))
df['valid_number'] = df['phone'].apply(lambda x: len(str(x)) == 11)
# Prepend 86 to phone number column
df['phone'] = ('86' + df['phone'])
Convert dataframe to csv file
df.to_csv('test.csv', index=False)
The json file I am using has thousands of rows
Thank you in advance!

In Pandas, how can I extract certain value using the key off of a dataframe imported from a csv file?

Using Pandas, I'm trying to extract value using the key but I keep failing to do so. Could you help me with this?
There's a csv file like below:
value
"{""id"":""1234"",""currency"":""USD""}"
"{""id"":""5678"",""currency"":""EUR""}"
I imported this file in Pandas and made a DataFrame out of it:
dataframe from a csv file
However, when I tried to extract the value using a key (e.g. df["id"]), I'm facing an error message.
I'd like to see a value 1234 or 5678 using df["id"]. Which step should I take to get it done? This may be a very basic question but I need your help. Thanks.

The csv file isn't being read in correctly.
You haven't set a delimiter; pandas can automatically detect a delimiter but hasn't done so in your case. See the read_csv documentation for more on this. Because the , the pandas dataframe has a single column, value, which has entire lines from your file as individual cells - the first entry is "{""id"":""1234"",""currency"":""USD""}". So, the file doesn't have a column id, and you can't select data by id.
The data aren't formatted as a pandas df, with row titles and columns of data. One option is to read in this data is to manually process each row, though there may be slicker options.
file = 'test.dat'
f = open(file,'r')
id_vals = []
currency = []
for line in f.readlines()[1:]:
## remove obfuscating characters
for c in '"{}\n':
line = line.replace(c,'')
line = line.split(',')
## extract values to two lists
id_vals.append(line[0][3:])
currency.append(line[1][9:])

You just need to clean up the CSV file a little and you are good. Here is every step:
# open your csv and read as a text string
with open('My_CSV.csv', 'r') as f:
my_csv_text = f.read()
# remove problematic strings
find_str = ['{', '}', '"', 'id:', 'currency:','value']
replace_str = ''
for i in find_str:
my_csv_text = re.sub(i, replace_str, my_csv_text)
# Create new csv file and save cleaned text
new_csv_path = './my_new_csv.csv' # or whatever path and name you want
with open(new_csv_path, 'w') as f:
f.write(my_csv_text)
# Create pandas dataframe
df = pd.read_csv('my_new_csv.csv', sep=',', names=['ID', 'Currency'])
print(df)
Output df:
ID Currency
0 1234 USD
1 5678 EUR

You need to extract each row of your dataframe using json.loads() or eval()
something like this:
import json
for row in df.iteritems():
print(json.loads(row.value)["id"])
# OR
print(eval(row.value)["id"])

Dictionary with csv files is not reading each column

I created a dictionary with several dataframes using the following code:
dataframes = {}
csv_root = Path(".")
for csv_path in csv_root.glob("*.csv"):
key = csv_path.stem # the filename without the ".csv" extension
dataframes[key] = pd.read_csv(csv_path, skiprows=1,delim_whitespace=True)
However, it is not recognizing all the columns contained within each dataframe, which are divided by a comma "," in csv format. Instead of recognizing 7 columns, it only recognizes 2.
Can someone help me to fix this?
Thanks in advance!

From the documentation :
delim_whitespacebool, default False
Specifies whether or not whitespace (e.g. ' ' or ' ') will be used as the sep. Equivalent to setting sep='\s+'. If this option is
set to True, nothing should be passed in for the delimiter parameter.
By setting this option, you are indicating to pandas to split your csv file on whitespaces rather than on commas (default behavior).
Try with
pd.read_csv(csv_path, skiprows=1)

delimit data on columns to new columns python

I want to delimit some data from a txt file into a dataframe, but when I open this file via pandas module, the data just has 1 column. I want to delimit this data into 17 columns. The data from txt file look like:
In python, I have the following code using pandas:
import pandas as pd
count=1
nama = 'Data/'+'%d.txt'%(count)
df = pd.read_table(nama,sep = '\t',header=None)
df_head1=df
df_sta=df
data_sta=df_sta.drop([0,1,2,3,4,5])
print(data_sta)
I need to split into columns like sta, date, time, Latitude, Longitude, and sta time. If i delimit in excel,the data i want look like :
The data i want
ps: i have used delim_whitespace=True, but that's not running and the message is :
pandas.errors.ParserError: Error tokenizing data. C error: Expected 3 fields in line 6, saw 4

if delimit by tab '\t' doesn't work use :
df = pd.read_table(filename,delim_whitespace=True,skiprows = 'number_of_rows_before_the_headers_start')
this is similar to using delimiter=r"\s+" but i feel the above method is faster than the regex.

How to read a file with a semi colon separator in pandas

I a importing a .csv file in python with pandas.
Here is the file format from the .csv :
a1;b1;c1;d1;e1;...
a2;b2;c2;d2;e2;...
.....
here is how get it :
from pandas import *
csv_path = "C:...."
data = read_csv(csv_path)
Now when I print the file I get that :
0 a1;b1;c1;d1;e1;...
1 a2;b2;c2;d2;e2;...
And so on... So I need help to read the file and split the values in columns, with the semi color character ;.

read_csv takes a sep param, in your case just pass sep=';' like so:
data = read_csv(csv_path, sep=';')
The reason it failed in your case is that the default value is ',' so it scrunched up all the columns as a single column entry.

In response to Morris' question above:
"Is there a way to programatically tell if a CSV is separated by , or ; ?"
This will tell you:
import pandas as pd
df_comma = pd.read_csv(your_csv_file_path, nrows=1,sep=",")
df_semi = pd.read_csv(your_csv_file_path, nrows=1, sep=";")
if df_comma.shape[1]>df_semi.shape[1]:
print("comma delimited")
else:
print("semicolon delimited")