I have a list of lists containing a varying number of strings in each sublist:
tq_list = [['The mysterious diary records the voice.', 'Italy is my favorite country', 'I am happy to take your donation', 'Any amount will be greatly appreciated.'], ['I am counting my calories, yet I really want dessert.', 'Cats are good pets, for they are clean and are not noisy.'], ['We have a lot of rain in June.']]
I would like to create a new CSV file for each sublist. All I have so far is a way to output each sublist as a row in the same CSV file using the following code:
name_list = ["sublist1","sublist2","sublist3"]
with open("{}.csv".format(*name_list), "w", newline="") as f:
writer = csv.writer(f)
for row in tq_list:
writer.writerow(row)
This creates a single CSV file named 'sublist1.csv'.
I've toyed around with the following code:
name_list = ["sublist1","sublist2","sublist3"]
for row in tq_list:
with open("{}.csv".format(*name_list), "w", newline="") as f:
writer = csv.writer(f)
writer.writerow(row)
Which also only outputs a single CSV file named 'sublist1.csv', but with only the values from the last sublist. I feel like this is a step in the right direction, but obviously not quite there yet.
What the * in "{}.csv".format(*name_list) in your code actually does is this: It unpacks the elements in name_list to be passed into the function (in this case format). That means that format(*name_list) is equivalent to format("sublist1", "sublist2", "sublist3"). Since there is only one {} in your string, all arguments to format except "sublist1" are essentially discarded.
You might want to do something like this:
for index, row in enumerate(tq_list):
with open("{}.csv".format(name_list[index]), "w", newline="") as f:
...
enumerate returns a counting index along with each element that it iterates over so that you can keep track of how many elements there have already been. That way you can write into a different file each time. You could also use zip, another handy function that you can look up in the Python documentation.
Related
I have this script that reads a CSV and saves the second column to a list, I'm trying to get it to write the contents of the list to a new CSV. The problem is every entry should have its own row but the new file sets everything into the same row.
I've tried moving the second with open code to within the first with open and I've tried adding a for loop to the second with open but no matter what I try I don't get the right results.
Here is the code:
import csv
col_store=[]
with open('test-data.csv', 'r') as rf:
reader = csv.reader(rf)
for row in reader:
col_store.append(row[1])
with open('meow.csv', 'wt') as f:
csv_writer = csv.writer(f)
csv_writer.writerows([col_store])
In your case if you have a column of single letters/numbers then Y.R answer will work.
To have a code that works in all cases, use this.
with open('meow.csv', 'wt') as f:
csv_writer = csv.writer(f)
csv_writer.writerows(([_] for _ in col_store))
From here it is mentioned that writerows expect an an iterable of row objects. Every row object should be an iterable of strings or numbers for Writer objects
The problem is that you are using 'writerows' treating 'col_store' as a list with one item.
The simplest approach to fixing this is calling
csv_writer.writerows(col_store)
# instead of
csv_writer.writerows([col_store])
However, this will lead to a probably unwanted result - having blank lines between the lines.
To solve this, use:
with open('meow.csv', 'wt', newline='') as f:
csv_writer = csv.writer(f)
csv_writer.writerows(col_store)
For more about this, see CSV file written with Python has blank lines between each row
Note: writerows expects 'an iterable of row objects' and 'row objects must be an interable of strings or numbers'.
(https://docs.python.org/3/library/csv.html)
Therefore, in the generic case (trying to write integers for examlpe), you should use Sam's solution.
I have a list of dictionaries
d = [{'value':'foo_1', 'word_list':['blah1', 'blah2']}, ...., {'value': 'foo_n', 'word_list':['meh1', 'meh2']}]
I want to write this to a CSV file with all the 'value' keys in one column, and then each individual word from the "value"'s word_list as its own column. So I have the first row as
foo_1 blah_1 blah_2
and so on.
I don't know how many dictionaries I have, or how many words I have in "word_list".
How would I go about doing this in Python 3?
Thanks!
I figured out a solution, but it's kind of messy (wow, I can't write a bit of code without it being in the "proper format"...how annoying):
with open('filename', 'w') as f:
for key in d.keys():
f.write("%s,"%(key))
for word in d[key]:
f.write("%s,"%(word))
f.write("\n")
You can loop through the dictionaries one at a time, construct the list and then use the csv module to write the data as I have shown here
import csv
d = [{'value':'foo_1', 'word_list':['blah1', 'blah2']}, {'value': 'foo_n', 'word_list':['meh1', 'meh2']}]
with open('test_file.csv', 'w') as file:
writer = csv.writer(file)
for val_dict in d:
csv_row = [val_dict['value']] + val_dict['word_list']
writer.writerow(csv_row)
It should work for word lists of arbitrary length and as many dictionaries as you want.
It would probably be easiest to flatten each row into a normal list before writing it to the file. Something like this:
with open(filename, 'w') as file:
writer = csv.writer(file)
for row in data:
out_row = [row['value']]
for word in row['word_list']:
out_row.append(word)
csv.writerow(out_row)
# Shorter alternative to the two loops:
# csv.writerow((row['value'], *row['word_list']) for row in data)
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.")
Need to search through data and delete customer Social Security Numbers.
with open('customerdata.csv') as csvfile:
reader = csv.DictReader(csvfile)
for row in reader:
data.append(row)
for row in customerdata.csv:
results = re.search(r'\d{3}-\d{2}-\d{4}', row)
re.replace(results, "", row)
print(results)
New to scripting and not sure what it is I need to do to fix this.
This is not a job for a regex.
You are using a csv.DictReader, which is awesome. This means you have access to the column names in your csv file. What you should do is make a note of the column that contains the SSN, then write out the row without it. Something like this (not tested):
with open('customerdata.csv') as csvfile:
reader = csv.DictReader(csvfile)
for row in reader:
del row['SSN']
print(row)
If you need to keep the data but blank it out, then something like:
with open('customerdata.csv') as csvfile:
reader = csv.DictReader(csvfile)
for row in reader:
row['SSN'] = ''
print(row)
Hopefully you can take things from here; for example, rather than printing, you might want to use a csv dict writer. Depends on your use case. Though, do stick with csv operations and definitely avoid regexes here. Your data is in csv format. Think about the data as rows and columns, not as individual strings to be regexed upon. :)
I'm not seeing a replace function for re in the Python 3.6.5 docs.
I believe the function you would want to use is re.sub:
re.sub(pattern, repl, string, count=0, flags=0)
Return the string obtained by replacing the leftmost non-overlapping occurrences of pattern in string by the replacement repl. If the pattern isn’t found, string is returned unchanged.
This means that all you need in your second for loop is:
for row in customerdata.csv:
results = re.sub(r'\d{3}-\d{2}-\d{4}', row, '')
print(results)
Here is my code:
import csv
with open("Grades.txt", "r") as file:
reader = csv.reader(file)
for row in reader:
if name == row[0]:
with open("Grades.txt", "a") as file:
writer = csv.writer(file)
writer.writerow(grade)
The variable name and grade have already been defined in an earlier function. I have a text file with a list of names so the code checks if the name(John) is in the text file and then is supposed to write the grade(A) next the name with a comma separating it. The problem is that my code will write the grade a space or 2 spaces below the entire list of names. If I can get it to write to the end of the name it would just be shown like (JohnA) with no separation. Im clueless about how to go about fixing this. I would appreciate if you could correct my code to do what I need it to. The variable name is an input from a login in a different function so the input is different every time. Also new names may be added through my sign up function so the similar question doesn't help.
for example say my text file looked like this:
John
Sam
Bob
And the grade Sam got was an A. How would I append the A grade to the end of Bobs name with a comma separating the name and the grade?
I don't see how this code example should do the job you describe. Sorry.
import csv
students = [["Anne", "A"], ["Emily", "B"]]
with open("grades.csv", "w", newline="") as f:
writer = csv.writer(f)
for row in students:
writer.writerow(row)
You must give a tupel or a list as a row to csv.writer. What you describe sounds that you write two times to that file, but I don't see that this is been done by your code as described.
I hope to help you a little bit. Sorry at the moment I can't comment...
New:
What I want to say is, that you should put the names and grades in your main program together and then write it to the file. This is how I would solve your task.
names = ["John", "Sam", "Bob"]
grades = ["A", "B", "C"]
names_grades = zip(names, grades)
for row in names_grades:
print(row)
The new row can be written easily to your file.