What I Want
I have written a code that opens a file (currentcode) gets it's text finds it in another file (text.txt) and replaces currentcode with a new int.
My Code
import os
currentcode = open('currentcode.txt','r+')
code = currentcode.read()
print('Choose File: ')
print('1: File One > ')
file = input('Enter Number Of File: ')
file = 'C:/text.txt'
old_text = code
new_text = str(int(code) + 1)
print('Opened File')
f1 = open(file, 'r')
f2 = open(file, 'w')
f2.write(replace(old_text, new_text))
currentcode.write(new_text)
f1.close()
f2.close()
Output After Running
When I Run This Code I Get:
Choose File:
1: File One >
Enter Number Of File: 1
Opened File
Traceback (most recent call last):
File "C:\Users\DanielandZoe\Desktop\scripys\Replace.py", line 18, in <module>
f2.write(replace(old_text, new_text))
NameError: name 'replace' is not defined
NameError: name 'replace' is not defined
That means python couldn't find a module, class or function called 'replace'.
If you want to replace text on a file, you need to get its contents as a string, not as a file-like object (like you're doing now), then you replace the contents using the replace method on your string and finally, write the contents to the desired file.
string.replace() is a method for strings:
https://docs.python.org/2/library/string.html#string.replace
what is in f2? Not a string. You should read the lines of the file.
I'm getting the following error when attempting to open a new file with today's date.
Traceback (most recent call last):
File "C:\BenPi\stacking\pi3\red_RTS\iotest.py", line 6, in <module>
f = io.open('%s',today, 'w')
TypeError: an integer is required
Here is my code
import datetime
import io
import os
today = datetime.date.today().strftime('%m_%d_%Y')
print (today)
f = io.open('%s',today, 'w')
f.write('first line \n')
f.write('second line \n')
f.close()
It is my understanding that this is an issue that arises when someone inadvertently uses os.open() instead of io.open(), which is why I specified the io option. It should be noted that the same error comes up regardless if I import the os module.
I'm using python 3.2.5
Thoughts?
You're not formatting correctly, you're using , instead of %:
f = io.open('%s'%today, 'w')
Besides, you can just do:
f = io.open(today, 'w')
The line
f = io.open('%s',today, 'w')
should have '%s' first argument the first argument must be the file name.
If you write it like:
f = io.open(today, 'w')
Just works. Also consider using the "with" statment so in case of an exception the stream will be close anyway such as:
with io.open(today, 'w') as f:
f.write("hello world")
I hope I have been helpful.
So I'm trying to use the csv module in python 3.3.2 but I am getting this error.
Traceback (most recent call last):
File "C:\Users\massi_000\Desktop\csv.py", line 1, in <module>
import csv
File "C:\Users\massi_000\Desktop\csv.py", line 4, in <module>
csv.reader(f)
AttributeError: 'module' object has no attribute 'reader'
Obviously I'm going something stupendously wrong but all the code I am using is below and it looks fine. Has something changed in this version that has rendered this code unusable or..?
import csv
f = open("test.csv")
csv.reader(f)
for row in csv_fi:
print(row)
f.close()
You have named your file csv.py and this clashes with the csv module from the Python standard library.
You should rename your own file to something else so that import csv will import the standard library module and not your own. This can be confusing but this is a good rule-of-thumb going forward: avoid giving your own Python files names that are the same as modules in the standard library.
As #Simeon Visser said, you have to rename your file but you have some other issues with your code as well. Try this:
import csv
with open('test.csv', newline='') as f:
reader = csv.reader(f, delimiter=' ')
for row in reader:
print (', '.join(row))
I am brand new to Python and am having a terrible time trying to read in a .csv file to work with. The code I am using is the following:
>>> dat = open('blue.csv','r')
>>> print dat()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: 'file' object is not callable
Could anyone help me diagnose this error or lend any suggestions on how to read the file in? Sorry if there is an answer to this question already, but I couldn't seem to find it.
You need to use read in order to read a file
dat = open('blue.csv','r')
print dat.read()
Alternatively, you can use with for self-closing
with open('blue.csv','r') as o:
data = o.read()
You can read the file:
dat = open('blue.csv', 'r').read()
Or you can open the file as a csv and read it row by row:
import csv
infile = open('blue.csv', 'r')
csvfile = csv.reader(infile)
for row in csvfile:
print row
column1 = row[0]
print column1
Check out the csv docs for more options for working with csv files.
I need to read a CSV file in python.
Since for last row I receive a 'NULL byte' error I would like to avoid using for keyword but the while.
Do you know how to do that?
reader = csv.reader( file )
for row in reader # I have an error at this line
# do whatever with row
I want to substitute the for-loop with a while-loop so that I can check if the row is NULL or not.
What is the function for reading a single row in the CSV module?
Thanks
Thanks
p.S. below the traceback
Traceback (most recent call last):
File "FetchNeuro_TodayTrades.py", line 189, in
for row in reader:
_csv.Error: line contains NULL byte
Maybe you could catch the exception raised by the CSV reader. Something like this:
filename = "my.csv"
reader = csv.reader(open(filename))
try:
for row in reader:
print 'Row read with success!', row
except csv.Error, e:
sys.exit('file %s, line %d: %s' % (filename, reader.line_num, e))
Or you could use next():
while True:
try:
print reader.next()
except csv.Error:
print "Error"
except StopIteration:
print "Iteration End"
break
You need (always) to say EXACTLY what is the error message that you got. Please edit your question.
Probably this:
>>> import csv; csv.reader("\x00").next()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
_csv.Error: line contains NULL byte
>>>
The csv module is not 8-bit clean; see the docs: """Also, there are currently some issues regarding ASCII NUL characters."""
The error message is itself in error: it should be "NUL", not "NULL" :-(
If the last line in the file is empty, you won't get an exception, you'll merely get row == [].
Assuming the problem is one or more NULs in your file(s), you'll need to (1) speak earnestly to the creator(s) of your file(s) (2) failing that, read the whole file in (mode="rb"), strip out the NUL(s), and feed fixed_text.splitlines() to the csv reader.
The Django community has addressed Python CSV import issues, so it might be worth searching for CSV import there, or posting a question. Also, you could edit the offending line directly in the CSV file before trying the import.
You could try cleaning the file as you read it:
def nonull(stream):
for line in stream:
yield line.replace('\x00', '')
f = open(filename)
reader = csv.reader(nonull(f))
Assuming, of course, that simply ignoring NULL characters will work for you!
If your problem is specific to the last line being empty, you can use numpy.genfromtxt (or the old matplotlib.mlab.csv2rec)
$: cat >csv_file.txt
foo,bar,baz
yes,no,0
x,y,z
$:
$: ipython
>>> from numpy import genfromtxt
>>> genfromtxt("csv_file.txt", dtype=None, delimiter=',')
array([['foo', 'bar', 'baz'],
['yes', 'no', '0'],
['x', 'y', 'z']],
dtype='|S3')
not really sure what you mean, but you can always check for existence with if
>>> reader = csv.reader("file")
>>> for r in reader:
... if r: print r
...
if this is not what you want, you should describe your problem more clearly by showing examples of things that doesn't work for you, including sample file format and desired output you want.
I don't have an answer, but I can confirm the problem, and that most answers posted don't work. You cannot catch this exception. You cannot test for if line. Maybe you could check for the NULL byte directly, but I'm not swift enough to do that... If it is always on the last line, you could of course skip that.
import csv
FH = open('data.csv','wb')
line1 = [97,44,98,44,99,10]
line2 = [100,44,101,44,102,10]
for n in line1 + line2:
FH.write(chr(n))
FH.write(chr(0))
FH.close()
FH = open('data.csv')
reader = csv.reader(FH)
for line in reader:
if '\0' in line: continue
if not line: continue
print line
$ python script.py
['a', 'b', 'c']
['d', 'e', 'f']
Traceback (most recent call last):
File "script.py", line 11, in <module>
for line in reader:
_csv.Error: line contains NULL byte
Process the initial csv file and replace the Nul '\0' with blank, and then you can read it.
The actual code looks like this:
data_initial = open(csv_file, "rU")
reader = csv.reader((line.replace('\0','') for line in data_initial))
It works for me.
And the original answer is here:csv-contain null byte