I am trying to write a simple program that should give the following output when it reads csv file which contains several email ids.
email_id = ['emailid1#xyz.com','emailid2#xyz.com','emailid3#xyz.com'] #required format
but the problem is the output I got is like this following:
[['emailid1#xyz.com']]
[['emailid1#xyz.com'], ['emailid2#xyz.com']]
[['emailid1#xyz.com'], ['emailid2#xyz.com'], ['emailid3#xyz.com']] #getting this wrong format
here is my piece of code that I have written: Kindly suggest me the correction in the following piece of code which would give me the required format. Thanks in advance.
import csv
email_id = []
with open('contacts1.csv', 'r') as file:
reader = csv.reader(file, delimiter = ',')
for row in reader:
email_id.append(row)
print(email_id)
NB.: Note my csv contains only one column that has email ids and has no header. I also tried the email_id.extend(row) but It did not work also.
You need to move your print outside the loop:
with open('contacts1.csv', 'r') as file:
reader = csv.reader(file, delimiter = ',')
for row in reader:
email_id.append(row)
print(sum(email_id, []))
The loop can also be like this (if you only need one column from the csv):
for row in reader:
email_id.append(row[0])
print(email_id)
Related
I have a .csv file with Bitcoin price and market data, and I want to get the 5th and 7th columns from the last row in the file. I have worked out how to get the last row, but I'm not sure how to extract columns (values) 5 and 7 from it. Code:
with open('BTCAUD_data.csv', mode='r') as BTCAUD_data:
writer = csv.reader(BTCAUD_data, delimiter=',')
data = list(BTCAUD_data)[-1]
print(data)
Edit: How would I also add column names, and would adding them help me? (I have already manually put the names into individual columns in the first line of the file itself)
Edit #2: Forget about the column names, they are unimportant. I still don't have a working solution. I have a vague idea that I'm not actually reading the file as a list, but rather as a string. (This means when I subscript the data variable, I get a single digit, rather than an item in a list) Any hints to how I read the line as a list?
Edit #3: I have got everything working to expectations now, thanks for everyone's help :)
Your code never uses the csv-reader. You can do so like this:
import csv
# This creates a file with demo data
with open('BTCAUD_data.csv', 'w') as f:
f.write(','.join( f"header{u}" for u in range(10))+"\n")
for l in range(20):
f.write(','.join( f"line{l}_{c}" for c in range(10))+"\n")
# this reads and processes the demo data
with open('BTCAUD_data.csv', 'r', newline="") as BTCAUD_data:
reader = csv.reader(BTCAUD_data, delimiter=',')
# 1st line is header
header = next(reader)
# skip through the file, row will be the last line read
for row in reader:
pass
print(header)
print(row)
# each row is a list and you can index into it
print(header[4], header[7])
print(row[4], row[7])
Output:
['header0', 'header1', 'header2', 'header3', 'header4', 'header5', 'header6', 'header7', 'header8', 'header9']
['line19', 'line19', 'line19', 'line19', 'line19', 'line19', 'line19', 'line19', 'line19', 'line19']
header4 header7
line19_4 line19_7
Better use pandas for handling CSV file.
import pandas as pd
df=pd.read_csv('filename')
df.column_name will give the corresponding column
If you read this csv file into df and try df.Year will give you the Year column.
I have this in csv file:
Titre,a,b,c,d,e
01,jean,paul,,
01,,,jack,
02,jeanne,jack,,
02,,,jean
and i want :
Titre,a,b,c,d,e
01,jean,paul,jack,
02,jeanne,jack,,jean
can you help me ?
In general, a good approach is to read the csv file and iterate through the rows using Python's CSV module.
CSV will create an iterator that will let you loop through your file like this:
import csv
with open('your filename.csv', 'r') as infile:
reader = csv.reader(infile)
for line in reader:
for value in line:
# Do your thing
You're going to need to construct a new data set that has different properties. The requirements you described:
Ignore any empty cells
Any time you encounter a row that has a new index number, add a new row to your new data set
Any time you encounter a row that has an index number you've seen before, add it to the row that you already created (except for that index number value itself)
I'm not writing that part of the code for you because you need to learn and grow. It's a good task for a beginner.
Once you've constructed that data set, it will look like this:
example_processed_data = [["Titre","a","b","c","d","e"],
["01","jean","paul","jack"],
["02","jeanne","jack","","jean"]]
You can then create a CSV writer, and create your outfile by iterating over that data, similarly to how you iterated over the infile:
with open('outfile.csv', 'w') as outfile:
writer = csv.writer(outfile)
for line in example_processed_data:
writer.writerow(line)
print("Done! Wrote", len(example_processed_data), "lines to outfile.csv.")
I am trying to extract data from a csv file with python 3.6.
The data are both numbers and text (it's url addresses):
file_name = [-0.47, 39.63, http://example.com]
On multiple forums I found this kind of code:
data = numpy.genfromtxt(file_name, delimiter=',', skip_header=skiplines,)
But this works for numbers only, the url addresses are read as NaN.
If I add dtype:
data = numpy.genfromtxt(file_name, delimiter=',', skip_header=skiplines, dtype=None)
The url addresses are read correctly, but they got a "b" at the beginning of the address, such as:
b'http://example.com'
How can I remove that? How can I just have the simple string of text?
I also found this option:
file = open(file_path, "r")
csvReader = csv.reader(file)
for row in csvReader:
variable = row[i]
coordList.append(variable)
but it seems it has some issues with python3.
I am trying read a CSV file into python 3 using unicodecsv library. Code follows :
with open('filename.csv', 'rb') as f:
reader = unicodecsv.DictReader(f)
Student_Data = list(reader)
But the order of the columns in the CSV file is not retained when I output any element from the Student_Data. The output contains any random order of the columns. Is there anything wrong with the code? How do I fix this?
As stated in csv.DictReader documentation, the DictReader object behaves like a dict - so it is not ordered.
You can obtain the list of the fieldnames with:
reader.fieldnames
But if you only want to obtain a list of the field values, in original order, you can just use a normal reader:
with open('filename.csv', 'rb') as f:
reader = unicodecsv.reader(f)
for row in reader:
Student_Data = row
I have the following problem:
I want to convert a tab delimited text file to a csv file. The text file is the SentiWS dictionary which I want to use for a sentiment analysis ( https://github.com/MechLabEngineering/Tatort-Analyzer-ME/tree/master/SentiWS_v1.8c ).
The code I used to do this is the following:
txt_file = r"SentiWS_v1.8c_Positive.txt"
csv_file = r"NewProcessedDoc.csv"
in_txt = csv.reader(open(txt_file, "r"), delimiter = '\t')
out_csv = csv.writer(open(csv_file, 'w'))
out_csv.writerows(in_txt)
This code writes everything in one row but I need the data to be in three rows as normally intended from the file itself. There is also a blank line under each data and I don´t know why.
I want the data to be in this form:
Row1 Row2 Row3
Word Data Words
Word Data Words
instead of
Row1
Word,Data,Words
Word,Data,Words
Can anyone help me?
import pandas
It will convert tab delimiter text file into dataframe
dataframe = pandas.read_csv("SentiWS_v1.8c_Positive.txt",delimiter="\t")
Write dataframe into CSV
dataframe.to_csv("NewProcessedDoc.csv", encoding='utf-8', index=False)
Try this:
import csv
txt_file = r"SentiWS_v1.8c_Positive.txt"
csv_file = r"NewProcessedDoc.csv"
with open(txt_file, "r") as in_text:
in_reader = csv.reader(in_text, delimiter = '\t')
with open(csv_file, "w") as out_csv:
out_writer = csv.writer(out_csv, newline='')
for row in in_reader:
out_writer.writerow(row)
There is also a blank line under each data and I don´t know why.
You're probably using a file created or edited in a Windows-based text editor. According to the Python 3 csv module docs:
If newline='' is not specified, newlines embedded inside quoted fields will not be interpreted correctly, and on platforms that use \r\n linendings on write an extra \r will be added. It should always be safe to specify newline='', since the csv module does its own (universal) newline handling.