The section of coding I've written is as such:
thing=9
text_file=open("something.txt", "a")
text_file.write("\n", str(thing))
text_file.close()
This always returns the error Type error: "write" only takes 1 argument. 2 given.
What I'm trying to do is that each time I run this code it writes on a new line rather than the same line. Right now, if this doesn't work, I'm a bit confused how to do this. Any help would be appreciated!
Add a newline to the end1 of the string with the + operator:
text_file.write(str(thing) + "\n")
1Note: If you add it to the front, you will get a blank line at the top of your file, which may not be what you want.
The python interpreter is correct in saying:
"write" only takes 1 argument. 2 given
Python's file methods are documented here.
All you need to be doing is concatenating your string with the newline character. You can do so by replacing:
text_file.write("\n", str(thing))
with:
text_file.write("\n" + str(thing))
This will write an empty line before writing out what you want. This might not be what you are looking for. Instead you can do:
text_file.write(str(thing) + '\n')
Related
I am unable to format the output of my text file as I want it. I have fooled around with this for almost an hour, to no avail, and it's driving me mad. I want the first four floats to be on one line, and the next 10 values to be delimited by new lines.
if not (debug_flag>0):
text_file = open("Markov.txt", "w")
text_file.write("%.2f,%.2f,%.2f,%.2f" % (prob_not_to_not,prob_not_to_occured, prob_occured_to_not, prob_occured_to_occured))
for x in xrange(0,10):
text_file.write("\n%d" % markov_sampler(final_probability))
text_file.close()
Does anyone know what the issue is? The output I'm getting is all on 1 line.
You have to put the line feed at the end of the first line for it to work.
Also your text editor may be configure to have the \r\n end of line( if you are using notepad ), in wich case you should be seeing everything in the same line.
The code with the desired output may look something like this
if not (debug_flag>0):
text_file = open("Markov.txt", "w")
text_file.write("%.2f,%.2f,%.2f,%.2f\n" % (prob_not_to_not,prob_not_to_occured, prob_occured_to_not, prob_occured_to_occured))
for x in xrange(0,10):
text_file.write("%d\n" % markov_sampler(final_probability))
text_file.close()
I've got a csv file that has around 100 rows. Some of the cells in the 100 rows have filepaths like:
C:\\\\Users\\\Simon\\\\Desktop\\\\file.jpg
I want to open the csv file in python and change only the rows that have triple-slashes and convert them to a single backslash. Here is my code so far:
import csv
with open('myCsvFile', 'rb') as csvfile:
SysIndexTwo = csv.reader(csvfile)
for allRows in SysIndexTwo:
if '\\\\' in allRows:
writer.writerows(allRows.replace('\\\\', '\\'))
Tried the suggestions and get the following error:
Traceback (most recent call last):
File "SIPHON2.py", line 7, in <module>
for allRows in SysIndexTwo:
ValueError: I/O operation on closed file
simon#ubuntu:~/Desktop$ python SIPHON2.py
Traceback (most recent call last):
File "SIPHON2.py", line 7, in <module>
for allRows in SysIndexTwo:
ValueError: I/O operation on closed file
This doesn't seem to work. Any ideas?
Thanks
You need to indent your actual processing. Right now, you drop out of the context manager (the with statement where you define your CSV reader) before you try to use it. Thus, you get the "IO operation on closed file" error because the context manager closed the file when you left it.
You want this:
with open('myCsvFile', 'rb') as csvfile:
reader = csv.reader(csvfile) # Simple names are good, esp. in small scope!
for row in reader: # Indent me!
pass # Do stuff here.
The with statement is handy for automatically closing files (among other things) for you. However, this means that any work you do that requires the file you're using must be done before you leave the block, because once you leave, the file is closed!
The csv reader doesn't read the whole file when you initialize it: it reads it on demand. Thus, you need to still be inside the block when you read lines from the csv reader.
Other Notes
You've got a bunch of other problems. You seem to be unsure whether you're trying to clean three or four backslashes--make sure you know what you're doing before you try to do it!
Your actual row replacement is broken, because as you've written it, allRows is a list, not a string, so you're probably not going to find the backslash pattern you're looking for. Instead, you need an inner loop to look through each cell in each row:
for row in reader:
corrected = []
for cell in row:
corrected.append(cell.replace('\\\\\\', '\\')) # Gross! See below.
writer.writerow(corrected)
Note that I can't see where writer is defined, but it looks like it might be subject to the same problem as your reader, if it's defined in a context manager someplace else!
Finally, raw strings are your friends (though they may not help you much here). In general, anytime you want a literal backslash in your strings, put an r in front of the string to save yourself a lot of headache. However, replacing odd numbers of backslashes is still a problem, because even raw strings cannot end in an odd number of backslashes.
So, to replace \\\ with \ (replace three backslashes with one), you'll have to double up on the backslashes like I did in the example above. If you wanted to replace four backslashes with two, you could use raw strings to your advantage: cell.replace(r'\\\\', r'\\') works just fine.
For posterity: you could also do something just as ugly, but in a different way, by adding a space to the end of the pattern strings so they no longer end with backslashes, and then stripping off the extra space. The following line replaces three backslashes with one, but it's much hackier (and slower if you're doing it a whole lot):
s = r'This is a \\\ string with \\\ sets \ of \\ three backslash\\\es.'
print(s.replace(r'\\\ '.strip(), r'\ '.strip()))
The slashes you're trying to match are getting treated as escapes, so '\\\\' is actually looking for '\\'.
Try using raw strings, i.e. r'\\\\' (you'll want to use raw strings for both the matching as well as the replace).
You could also double up the slashes, so use \\ everytime you want \, but that gets cumbersome very quickly
Try:
allRows.replace('\\\\\\', '\\')
Please note that the \ symbols needs to be escaped, by doubling.
>>> d
'C:\\\\\\Users\\\\\\Simon\\\\\\Desktop\\\\\\file.jpg\n'
>>> d.replace('\\\\\\', '\\')
'C:\\Users\\Simon\\Desktop\\file.jpg\n'
>>> print d.replace('\\\\\\', '\\')
C:\Users\Simon\Desktop\file.jpg
I am creating a simple file in python to reorganize some text data I grabbed from a website. I put the data in a .txt file and then want to use the "tail" command to get rid of the first 5 lines. I'm able to make this work for a simple filename shown below, but when I try to change the filename (to what I'd actually like it to be) I get an error. My code:
start = 2010
end = 2010
for i in range(start,end+1)
year = str(i)
...write data to a file called file...
teamname=open(file).readline() # want to use this in the new filename
teamfname=teamname.replace(" ","") #getting rid of spaces
file2 = "gotdata2_"+year+".txt"
os.system("tail -n +5 gotdata_"+year+".txt > "+file2)
The above code works as intended, creating file, then creating file2 that excludes the first 5 lines of file. However, when I change the name of file2 to be:
file2 = teamfname+"_"+year+".txt"
I get the error:
sh: line 1: _2010.txt: command not found
It's as if the end of my file2 statement is getting chopped off and the .txt part isn't being recognized. In this case, my code outputs a file but is missing the _2010.txt at the end. I've double checked that both year and teamfname are strings. I've also tried it with and without spaces in the teamfname string. I get the same error when I try to include a os.system mv statement that would rename the file to what I want it to be, so there must be something wrong with my understanding of how to specify the string here.
Does anyone have any ideas about what causes this? I haven't been able to find a solution, but I've found this problem difficult to search for.
Without knowing what your actual strings are, it's impossible to be sure what the problem is. However, it's almost certainly something to do with failing to properly quote and/or escape arguments for the command line.
My first guess would be that you have a newline in the middle of your filename, and the shell is truncating the command at the newline. But I wouldn't bet too heavily on that. If you actually printed out the repr of the pathname, I could tell you for sure. But why go through all this headache?
The solution to almost any problem with os.system is to not use os.system.
If you look at the docs, they even tell you this:
The subprocess module provides more powerful facilities for spawning new processes and retrieving their results; using that module is preferable to using this function. See the Replacing Older Functions with the subprocess Module section in the subprocess documentation for some helpful recipes.
If you use subprocess instead of os.system, you can avoid the shell entirely. You can also pass arguments as a list instead of trying to figure out how to quote them and escape them properly. Which would completely avoid the exact problem you're having.
For example, if you do this:
file2 = "gotdata2_"+year+".txt"
with open(file2, 'wb') as f:
subprocess.check_call(['tail', '-n', '+5', "gotdata_"+year+".txt"], stdout=f)
Then, if you change that first line to this:
file2 = teamfname+"_"+year+".txt"
It will still work even if teamfname has a space or a quote or another special character in it.
That being said, I'm not sure why you want to use tail in the first place. You can skip the first 5 lines just as easily directly in Python.
I would like to read the next logical line from a file into python, where logical means "according to the syntax of python".
I have written a small command which reads a set of statements from a file, and then prints out what you would get if you typed the statements into a python shell, complete with prompts and return values. Simple enough -- read each line, then eval. Which works just fine, until you hit a multi-line string.
I'm trying to avoid doing my own lexical analysis.
As a simple example, say I have a file containing
2 + 2
I want to print
>>> 2 + 2
4
and if I have a file with
"""Hello
World"""
I want to print
>>>> """Hello
...World"""
'Hello\nWorld'
The first of these is trivial -- read a line, eval, print. But then I need special support for comment lines. And now triple quotes. And so on.
You may want to take a look at the InteractiveInterpreter class from the code module .
The runsource() method shows how to deal with incomplete input.
Okay, so resi had the correct idea. Here is my trivial code which does the job.
#!/usr/bin/python
import sys
import code
class Shell(code.InteractiveConsole):
def write(data):
print(data)
cons = Shell()
file_contents = sys.stdin
prompt = ">>> "
for line in file_contents:
print prompt + line,
if cons.push(line.strip()):
prompt = "... "
else:
prompt = ">>> "
I'm writing a script to convert very simple function documentation to XML in python. The format I'm using would convert:
date_time_of(date) Returns the time part of the indicated date-time value, setting the date part to 0.
to:
<item name="date_time_of">
<arg>(date)</arg>
<help> Returns the time part of the indicated date-time value, setting the date part to 0.</help>
</item>
So far it works great (the XML I posted above was generated from the program) but the problem is that it should be working with several lines of documentation pasted, but it only works for the first line pasted into the application. I checked the pasted documentation in Notepad++ and the lines did indeed have CRLF at the end, so what is my problem?
Here is my code:
mainText = input("Enter your text to convert:\r\n")
try:
for line in mainText.split('\r\n'):
name = line.split("(")[0]
arg = line.split("(")[1]
arg = arg.split(")")[0]
hlp = line.split(")",1)[1]
print('<item name="%s">\r\n<arg>(%s)</arg>\r\n<help>%s</help>\r\n</item>\r\n' % (name,arg,hlp))
except:
print("Error!")
Any idea of what the issue is here?
Thanks.
input() only reads one line.
Try this. Enter a blank line to stop collecting lines.
lines = []
while True:
line = input('line: ')
if line:
lines.append(line)
else:
break
print(lines)
The best way to handle reading lines from standard input (the console) is to iterate over the sys.stdin object. Rewritten to do this, your code would look something like this:
from sys import stdin
try:
for line in stdin:
name = line.split("(")[0]
arg = line.split("(")[1]
arg = arg.split(")")[0]
hlp = line.split(")",1)[1]
print('<item name="%s">\r\n<arg>(%s)</arg>\r\n<help>%s</help>\r\n</item>\r\n' % (name,arg,hlp))
except:
print("Error!")
That said, It's worth noting that your parsing code could be significantly simplified with a little help from regular expressions. Here's an example:
import re, sys
for line in sys.stdin:
result = re.match(r"(.*?)\((.*?)\)(.*)", line)
if result:
name = result.group(1)
arg = result.group(2).split(",")
hlp = result.group(3)
print('<item name="%s">\r\n<arg>(%s)</arg>\r\n<help>%s</help>\r\n</item>\r\n' % (name,arg,hlp))
else:
print "There was an error parsing this line: '%s'" % line
I hope this helps you simplify your code.
Patrick Moriarty,
It seems to me that you didn't particularly mention the console and that your main concern is to pass several lines together at one time to be treated. There's only one manner in which I could reproduce your problem: it is, executing the program in IDLE, to copy manually several lines from a file and pasting them to raw_input()
Trying to understand your problem led me to the following facts:
when data is copied from a file and pasted to raw_input() , the newlines \r\n are transformed into \n , so the string returned by raw_input() has no more \r\n . Hence no split('\r\n') is possible on this string
pasting in a Notepad++ window a data containing isolated \r and \n characters, and activating display of the special characters, it appears CR LF symbols at all the extremities of the lines, even at the places where there are \r and \n alone. Hence, using Notepad++ to verify the nature of the newlines leads to erroneous conclusion
.
The first fact is the cause of your problem. I ignore the prior reason of this transformation affecting data copied from a file and passed to raw_input() , that's why I posted a question on stackoverflow:
Strange vanishing of CR in strings coming from a copy of a file's content passed to raw_input()
The second fact is responsible of your confusion and despair. Not a chance....
.
So, what to do to solve your problem ?
Here's a code that reproduce this problem. Note the modified algorithm in it, replacing your repeated splits applied to each line.
ch = "date_time_of(date) Returns the time part.\r\n"+\
"divmod(a, b) Returns quotient and remainder.\r\n"+\
"enumerate(sequence[, start=0]) Returns an enumerate object.\r\n"+\
"A\rB\nC"
with open('funcdoc.txt','wb') as f:
f.write(ch)
print "Having just recorded the following string in a file named 'funcdoc.txt' :\n"+repr(ch)
print "open 'funcdoc.txt' to manually copy its content, and paste it on the following line"
mainText = raw_input("Enter your text to convert:\n")
print "OK, copy-paste of file 'funcdoc.txt' ' s content has been performed"
print "\nrepr(mainText)==",repr(mainText)
try:
for line in mainText.split('\r\n'):
name,_,arghelp = line.partition("(")
arg,_,hlp = arghelp.partition(") ")
print('<item name="%s">\n<arg>(%s)</arg>\n<help>%s</help>\n</item>\n' % (name,arg,hlp))
except:
print("Error!")
.
Here's the solution mentioned by delnan : « read from the source instead of having a human copy and paste it. »
It works with your split('\r\n') :
ch = "date_time_of(date) Returns the time part.\r\n"+\
"divmod(a, b) Returns quotient and remainder.\r\n"+\
"enumerate(sequence[, start=0]) Returns an enumerate object.\r\n"+\
"A\rB\nC"
with open('funcdoc.txt','wb') as f:
f.write(ch)
print "Having just recorded the following string in a file named 'funcdoc.txt' :\n"+repr(ch)
#####################################
with open('funcdoc.txt','rb') as f:
mainText = f.read()
print "\nfile 'funcdoc.txt' has just been opened and its content copied and put to mainText"
print "\nrepr(mainText)==",repr(mainText)
print
try:
for line in mainText.split('\r\n'):
name,_,arghelp = line.partition("(")
arg,_,hlp = arghelp.partition(") ")
print('<item name="%s">\n<arg>(%s)</arg>\n<help>%s</help>\n</item>\n' % (name,arg,hlp))
except:
print("Error!")
.
And finally, here's the solution of Python to process the altered human copy: providing the splitlines() function that treat all kind of newlines (\r or \n or \r\n) as splitters. So replace
for line in mainText.split('\r\n'):
by
for line in mainText.splitlines():