I've tried many solutions to add a header to my csv file, but nothing's working properly. Here they are :
I used the writerow method, but my data are overwriting the first row.
I used the DictWriter method, but I don't know how to fill it correctly. Here is my code:
csv = csv.DictWriter(open(directory +'/csv.csv', 'wt'), fieldnames = ["stuff1", "stuff2", "stuff3"], delimiter = ';')
csv.writeheader(["stuff1", "stuff2", "stuff3"])
I got a "2 arguments instead of one" error and I really don't know why.
Any advice?
All you need to do is call DictWriter.writeheader() without arguments:
with open(os.path.join(directory, 'csv.csv'), 'wb') as csvfile:
writer = csv.DictWriter(csvfile, fieldnames = ["stuff1", "stuff2", "stuff3"], delimiter = ';')
writer.writeheader()
You already told DictWriter() what your headers are.
I encountered a similar problem when writing the CSV file.
I had to read the csv file and modify some of the fields in it.
To write the header in the CSV file, i used the following code:
reader = csv.DictReader(open(infile))
headers = reader.fieldnames
with open('ChartData.csv', 'wb') as outcsv:
writer1 = csv.writer(outcsv)
writer1.writerow(headers)
and when you write the data rows, you can use a DictWriter in the following way
writer = csv.DictWriter(open("ChartData.csv", 'a' ), headers)
In the above code "a" stands for appending.
In conclusion - > use a to append data to csv after you have written your header to the same file
Related
for my university project i have to collect some data from github using the API. I save the result of my api call into a json file and after that i have to convert the json file into a csv file.
i use the following code to conver the json file to a csv:
with open ("data.json", "r") as f:
data = json.load(f)
with open('data.csv', 'w') as f:
fieldnames = data[0].keys()
writer = csv.DictWriter(f, fieldnames=fieldnames)
writer.writeheader()
for res in range(len(data)):
writer.writerow(data[res])
My problem is that in the json file i have some key/value pair as i follow:
"title" : "Hello \n World"
The "\n" is taken as newline i think because it will split the row of my csv file. How solve this problem? Anyway to make my code to ignore the "\n"?
bad output
output that i want
Did you check the string.replace() method like mystring.replace('\n', ' ')?
pandas can handle this:
import pandas as pd
df = pd.read_json('data.json')
df.to_csv('data.csv')
Or since you are opening the file in Excel you could write to xlsx directly:
df.to_excel('data.xlsx')
If you still wish to remove the newlines you can use any of these solutions prior to saving the dataframe.
I have some vocabulary and their counterparts to create an Anki deck. I need the program to write the output of my code in two columns of a csv file; first for the vocabulary and second for the meaning. I've tried two codes but neither of them worked. How can I solve this problem?
Notebook content(vocab):
obligatory,義務的
sole,単独,唯一
defined,一定
obey,従う
...
First try:
with open("C:/Users/berka/Desktop/Vocab.txt") as csv_file:
csv_reader = csv.reader(csv_file)
with open("C:/Users/berka/Desktop/v.csv", "w", newline="") as new_file:
csv_writer = csv.writer(new_file, delimiter=",")
for line in csv_reader:
csv_writer.writerow(line)
Second try:
with open("C:/Users/berka/Desktop/Vocab.txt") as csv_file:
csv_reader = csv.DictReader(csv_file)
with open("C:/Users/berka/Desktop/v.csv", "w",) as f:
field_names = ["Vocabulary", "Meaning"]
csv_writer = csv.DictWriter(f, fieldnames=field_names, extrasaction="ignore")
csv_writer.writeheader()
for line in csv_reader:
csv_writer.writerow(line)
Result of the first try:
https://cdn.discordapp.com/attachments/696432733882155138/746404430123106374/unknown.png
#Second try was not even close
Expected result:
https://cdn.discordapp.com/attachments/734460259560849542/746432094825087086/unknown.png
Like Kevin said, Excel uses ";" as delimiter and your csv code creates a csv file with comma(,) delimiter. That's why it's shown with commas in your Csv Reader. You can pass ";" as delimiter if you want Excel to read your file correctly. Or you can create a csv file with your own Csv Reader and read it with notepad if you want to see which delimiter it uses.
Your first try works, it's the app you're using for importing that is not recognizing the , as the delimiter. I'm not sure where you're importing this to, but at least in Google Sheets you can choose what the delimiter is, even after the fact.
My situation is, I have csv file and here is its code.
user_file = Path(str(message.author.id) + '.cvs')
if user_file.exists():
with open('test.csv', 'a') as fp:
writer = csv.writer(fp, delimiter=',')
writer.writerows(data)
else:
with open(user_file, 'w') as fp:
data = [('xp', 0)]
writer = csv.writer(fp, delimiter=',')
writer.writerows(data)
I'm wanting a csv file that keeps track of how many times they type a message so i need a way of editing the csv file and adding 1 to what it already has. But i have no idea how to do that! please help!<3
test.csv:
4
Python:
# Replace test.csv with the file you wish to open. Keep "w+"
with open("test.csv", "w+") as dat:
# Assumes the text in the file is an int
n = int(dat.read())
dat.write(str(n+1))
Result in test.csv:
5
This way it opens the file as write and read, reads the number, then writes it back as a string. Note that write() will override any text in the current file, so you don't need to remove the text
P.S if that if else statement is to check the file actually exists, it's unnecessary. If you try to open() a file which doesn't exist, python will create it for you.
This:
import csv
with open('original.csv', 'rb') as inp, open('new.csv', 'wb') as out:
writer = csv.writer(out)
for row in csv.reader(inp):
if row[2] != "0":
writer.writerow(row)
os.remove('original.csv')
os.rename('new.csv', 'original.csv')
allows to delete certain rows of a CSV.
Is there a more pythonic way to delete some rows of a CSV file, in-place? (instead of creating a file, deleting the original, renaming, etc.)
There isn't a more Pythonic way: you can't delete stuff in the middle of a file. Write out a new file with the stuff you want, and then rename it.
I noticed that your code does not import the os module, even though you're using it. Regardless, here's a method of doing what you need it to do without using that module.
This will open in read mode first to get the data, then write mode to overwrite. Note that you need to pass the csv.reader(f) statement to the list() function or else the data variable will simply point to the memory address of the CSV file and you won't be able to do anything with the content once it's closed. list() will actually copy the information for you.
import csv
with open("original.csv", "rb") as f:
data = list(csv.reader(f))
with open("original.csv", "wb") as f:
writer = csv.writer(f)
for row in data:
if row[2] != "0":
writer.writerow(row)
I'm attempting to rewrite specific cells in a csv file using Python.
However, whenever I try to modify an aspect of the csv file, the csv file ends up being emptied (the file contents becomes blank).
Minimal code example:
import csv
ReadFile = open("./Resources/File.csv", "rt", encoding = "utf-8-sig")
Reader = csv.reader(ReadFile)
WriteFile = open("./Resources/File.csv", "wt", encoding = "utf-8-sig")
Writer = csv.writer(WriteFile)
for row in Reader:
row[3] = 4
Writer.writerow(row)
ReadFile.close()
WriteFile.close()
'File.csv' looks like this:
1,2,3,FOUR,5
1,2,3,FOUR,5
1,2,3,FOUR,5
1,2,3,FOUR,5
1,2,3,FOUR,5
In this example, I'm attempting to change 'FOUR' to '4'.
Upon running this code, the csv file becomes empty instead.
So far, the only other question related to this that I've managed to find is this one, which does not seem to be dealing with rewriting specific cells in a csv file but instead deals with writing new rows to a csv file.
I'd be very grateful for any help anyone reading this could provide.
The following should work:
import csv
with open("./Resources/File.csv", "rt", encoding = "utf-8-sig") as ReadFile:
lines = list(csv.reader(ReadFile))
with open("./Resources/File.csv", "wt", encoding = "utf-8-sig") as WriteFile:
Writer = csv.writer(WriteFile)
for line in lines:
line[3] = 4
Writer.writerow(line)
When you open a writer with w option, it will delete the contents and start writing the file anew. The file is therefore, at the point when you start to read, empty.
Try writing to another file (like FileTemp.csv) and at the end of the program renaming FileTemp.csv to File.csv.