I am trying to run through an excel file line by line and create a new list and then append every cell value on that line to the list. I don't think my code is correct but I just want to know why it cannot find the file, this is the error message.
def createPersonList(fileName):
open(fileName)
i = 0.0
for line in fileName:
i += 1
Person = []
for cell in line:
Person.append(cell)
return Person
error message:
createPersonList(personData.csv) Traceback (most recent call last):
File "<ipython-input-36-207031458d64>", line 1, in <module>
createPersonList(personData.csv) NameError: name 'personData' is not defined
I don't understand very well what you want, and also i don't know your structure of file.
But that's something similar with what you want:
import csv
def createPersonList(fileName):
personList = []
with open(fileName, 'r') as csv_file:
csv_reader = csv.reader(csv_file, delimiter='\t')
next(csv_reader, None)
for row in csv_reader:
for column in row:
personList.append(column)
return personList
Related
I am trying to do a relatively simple parse of a csv file, and I don't understand why the csv module is not working. Here is my code:
import csv
def getFromCSV(fileName):
with open(fileName, 'r') as f:
reader = csv.reader(f)
data = list(reader)
return data
def append_row(fileName, my_list):
with open(fileName, 'a') as output:
writer = csv.writer(output)
writer.writerow(my_list)
data = getFromCSV('dh_internal_all.csv')
for row in data:
if '25252' not in row:
print(row)
append_row('parsed.csv',[row])
This returns:
dh-dfbhv2l:Documents jwr38$ python3 remove_bad_data.py
Traceback (most recent call last):
File "remove_bad_data.py", line 13, in <module>
data = getFromCSV('dh_internal_all.csv')
File "remove_bad_data.py", line 3, in getFromCSV
reader = csv.reader(f)
NameError: name 'csv' is not defined
Thank you in advance for any tips.
EDIT: when I run python3 in terminal, then import csv, and then csv, it seems to recognize it, it returns:
<module 'csv' from '/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.7/lib/python3.7/csv.py'>
You pasted the wrong code. In your traceback, the faulting line is 3, but in this code, it's 5 - the two missing lines are probably the "import csv" lines.
Hi I'm trying to open simple csv file with the header from an external file:
got next file named: name.csv with next content:
Leo,Days,Ju
Tomas,Lee,Bruce
Max,Perez,Smith
If I code:
import csv
sep = ','
with open('name.csv') as csvfile:
fieldnames = ['name', 'paterno', 'materno']
reader = csv.DictReader(csvfile,fieldnames)
for row in reader:
list = (row['name'], \
row['materno'])
print (sep.join(list))
The result is desired like:
Leo,Ju
Tomas,Bruce
Max,Smith
But if got an extra file with headers named hdr_name.txt with:
['name', 'paterno', 'materno']
With this new code:
import csv
sep = ','
fieldnames = open('hdr_name.txt', 'r').read()
with open('name.csv') as csvfile:
print(fieldnames)
reader = csv.DictReader(csvfile,fieldnames)
for row in reader:
list = (row['name'], \
row['materno'])
print (sep.join(list))
Got as result:
Traceback (most recent call last):
File "<stdin>", line 5, in <module>
KeyError: 'name'
But if I ask for 'name' in fieldnames, is there!
>>> 'name' in fieldnames
True
>>>
What I'm doing wrong, with opening header from external file ?
fieldnames is a string that looks like this:
"['name', 'paterno', 'materno']"
Naturally, a membership test will return true, but that does not imply fieldnames is a list. Remember, file.read returns a string - you still need to cast it to a list.
This doesn't appear to look like JSON, so I'd recommend ast:
import ast
with open('hdr_name.txt', 'r') as f:
fieldnames = ast.literal_eval(f.read().strip())
scenario:
I'm trying to extract tweets from twitter, which is working fine,
next I'm trying to merge 10 files into 1(say file = QW).
for line in file:
my_row = [line]
filename = line.rstrip()+"_tweets"+".csv"
if(os.path.exists(filename)):
f = open(filename, "rt")
reader = csv.reader(f, delimiter="\t")
for line in enumerate(reader):
my_row.append(line)
writer.writerow(my_row)
else:
print(""+filename+ " doesnt exist")
my csv file looks like this
and then I will process that one file
problem: I want to read specific column of that CSV(QW) file
I tried row[0]
for row in input_file:
name_list = [] ;score = 0;
name_list.append(row[0])
print(name_list)
for a in row:
if a.find(skill_input) > 0 :
score = score+1;
name_list.append(score)
print(name_list)
writer.writerow([name_list])
and that point I get an error
my csv file looks like this
name_list.append(row[0])
IndexError: list index out of range
Try this
for line in open("csvfile.csv"):
csv_row = line.split(your_delimiter) #returns a list ["1","50","60"]
if not csv_row[k]:
continue
name_list.append(csv_row[k]) # Or csv_row[k] for specific kth column
I'm creating a csv.reader object, setting it as an instance variable, but then when I try to iterate through it I get an error saying I'm trying to operate on a closed file. Is the reader still linked to the file somehow? I'm assigning it within my with open(blah) block, so I'm confused as to why this is happening.
Here is my code:
def __init__(self, infile, header_file, transact_file):
self.infile = infile
self.header_of = header_file
self.transact_of = transact_file
def create_reader(self):
"""Create a csv reader."""
with open(self.infile, 'r') as inf:
logging.info('Infile name: {0}'.format(inf))
self.csv_reader = reader(inf, quotechar='"')
def parse_headers(self):
"""Separate header files ("H", "S") from transaction files."""
headers = []
transactions = []
for row in self.csv_reader:
row_type = row[0]
logging.info('Row type is: {0}'.format(row_type))
if row_type == 'H':
logging.info('Row added to header list.')
headers.append(row)
elif row_type == 'S':
if row not in headers:
logging.info('Row added to header list.')
headers.append(row)
else:
logging.info('Row added to transaction list.')
transactions.append(row)
# Debugging and verification
logging.info('Header list contains: {0}'.format('\n'.join([str(header) for header
in headers])))
logging.info('Transaction list contains: {0}'.format(
'\n'.join([str(trans) for trans in transactions])))
Here is my error stack:
Traceback (most recent call last): x
File "./gen_pre.py", line 155, in <module> x
main() x
File "./gen_pre.py", line 25, in main x
parser.run_process() x
File "./gen_pre.py", line 140, in run_process x
self.parse_headers() x
File "./gen_pre.py", line 68, in parse_headers x
for row in self.csv_reader: x
ValueError: I/O operation on closed file
with automatically closes the file when you leave the block.
You have to do
self.inf = open(self.infile, 'r')
self.csv_reader = reader(self.inf, quotechar='"') # self.inf
and you will have to close the file manually.
def close_reader(self):
self.csv_reader.close()
self.inf.close()
Context managers are great because they automatically close files for you. Instead of manually opening and closing the file, you could read the whole file and pass a list of the rows to the CSV reader:
def create_reader(self):
"""Create a csv reader."""
with open(self.infile, 'r') as inf:
logging.info('Infile name: {0}'.format(inf))
file_data = inf.readlines()
self.csv_reader = reader(file_data, quotechar='"')
The csv.reader object will accept anything it can iterate over, so a list of each line in the file (from readlines) will work fine.
I'm a QA tester who is new to python, trying to create a script to create multiple XML files from a CSV file containing various fields. I feel I am close to creating this program. Unfortunately,I have been getting the following error when adding code to advance to the next line in the CSV file(line = next(reader)).If I don't add the line to to advance, the program will run but multiple xml files will be created with information from only the first line of the CSV file. I can't figure out why or how to fix it.
Error Message:
Traceback (most recent call last):
File "C:\Users\xxxxxxxxx\Desktop\defxmlImportcsv.py", line 22, in <module>
line = next(reader)
ValueError: I/O operation on closed file.
Here is my code:
import xml.etree.ElementTree as etree
import csv
with open('datanames.csv') as csvfile:
reader = csv.reader(csvfile)
x=0
line = next(reader)
line = next(reader)
while x<2:
filename = "Output"+str(x)+".xml"
[firstName,lastName] = line
print(line)
tree = etree.parse('WB5655(BR-09).xml')
root = tree.getroot()
registration_id=tree.find('primaryApplicant/ssn')
registration_id.text = str(53)
first_name = tree.find('primaryApplicant/firstName')
first_name.text = (line[0])
last_name = tree.find('primaryApplicant/lastName')
last_name.text =(line[1])
line = next(reader)
tree.write(filename)
print(x)
x=x+1
Any help would be greatly appreciated. Thanks in advance.
csvfile is automatically closed when you exit your with block. Which means that reader, in turn, can no longer read from it, causing your line = next(reader) line to fail.
The easiest (and likely most correct) fix is to add indentation to your code so that your while loop is inside the with block.
You exited the with statement:
with open('datanames.csv') as csvfile:
reader = csv.reader(csvfile)
x=0
line = next(reader)
line = next(reader)
while x<2:
# ...
The moment the while line is reached the csvfile file object is closed, because, logically, that block is outside of the with statement (not matching the indentation).
The solution is to indent the whole while loop to be within the with block:
with open('datanames.csv') as csvfile:
reader = csv.reader(csvfile)
x=0
line = next(reader)
line = next(reader)
while x<2:
# ...
Rather than use while, use itertools.islice() to loop just twice:
from itertools import islice
tree = etree.parse('WB5655(BR-09).xml')
registration_id=tree.find('primaryApplicant/ssn')
registration_id.text = '53'
with open('datanames.csv') as csvfile:
reader = csv.reader(csvfile)
# skip two lines
next(islice(reader, 2, 2), None)
for x, row in enumerate(islice(reader, 2)):
filename = "Output{}.xml".format(x)
first_name = tree.find('primaryApplicant/firstName')
last_name = tree.find('primaryApplicant/lastName')
first_name.text, last_name.text = row
tree.write(filename)
I simplified your XML handling as well; you don't have to read the input XML tree twice, for example.