Printing without newline (print 'a',) prints a space, how to remove?
Question:
I have this code:
>>> for i in xrange(20):
... print 'a',
...
a a a a a a a a a a a a a a a a a a a a
I want to output 'a', without ' ' like this:
aaaaaaaaaaaaaaaaaaaa
Is it possible?
Answers:
without what?
do you mean
>>> print 'a' * 20
aaaaaaaaaaaaaaaaaaaa
?
You can suppress the space by printing an empty string to stdout between the print statements.
>>> import sys
>>> for i in range(20):
... print 'a',
... sys.stdout.write('')
...
aaaaaaaaaaaaaaaaaaaa
However, a cleaner solution is to first build the entire string you’d like to print and then output it with a single print statement.
You could print a backspace character ('b'):
for i in xrange(20):
print 'ba',
result:
aaaaaaaaaaaaaaaaaaaa
From PEP 3105: print As a Function in the What’s New in Python 2.6 document:
>>> from __future__ import print_function
>>> print('a', end='')
Obviously that only works with python 3.0 or higher (or 2.6+ with a from __future__ import print_function at the beginning). The print statement was removed and became the print() function by default in Python 3.0.
Python 3.x:
for i in range(20):
print('a', end='')
Python 2.6 or 2.7:
from __future__ import print_function
for i in xrange(20):
print('a', end='')
There are a number of ways of achieving your result. If you’re just wanting a solution for your case, use string multiplication as @Ant mentions. This is only going to work if each of your print statements prints the same string. Note that it works for multiplication of any length string (e.g. 'foo' * 20 works).
>>> print 'a' * 20
aaaaaaaaaaaaaaaaaaaa
If you want to do this in general, build up a string and then print it once. This will consume a bit of memory for the string, but only make a single call to print. Note that string concatenation using += is now linear in the size of the string you’re concatenating so this will be fast.
>>> for i in xrange(20):
... s += 'a'
...
>>> print s
aaaaaaaaaaaaaaaaaaaa
Or you can do it more directly using sys.stdout.write(), which print is a wrapper around. This will write only the raw string you give it, without any formatting. Note that no newline is printed even at the end of the 20 as.
>>> import sys
>>> for i in xrange(20):
... sys.stdout.write('a')
...
aaaaaaaaaaaaaaaaaaaa>>>
Python 3 changes the print statement into a print() function, which allows you to set an end parameter. You can use it in >=2.6 by importing from __future__. I’d avoid this in any serious 2.x code though, as it will be a little confusing for those who have never used 3.x. However, it should give you a taste of some of the goodness 3.x brings.
>>> from __future__ import print_function
>>> for i in xrange(20):
... print('a', end='')
...
aaaaaaaaaaaaaaaaaaaa>>>
If you want them to show up one at a time, you can do this:
import time
import sys
for i in range(20):
sys.stdout.write('a')
sys.stdout.flush()
time.sleep(0.5)
sys.stdout.flush() is necessary to force the character to be written each time the loop is run.
Just as a side note:
Printing is O(1) but building a string and then printing is O(n), where n is the total number of characters in the string. So yes, while building the string is “cleaner”, it’s not the most efficient method of doing so.
The way I would do it is as follows:
from sys import stdout
printf = stdout.write
Now you have a “print function” that prints out any string you give it without returning the new line character each time.
printf("Hello,")
printf("World!")
The output will be: Hello, World!
However, if you want to print integers, floats, or other non-string values, you’ll have to convert them to a string with the str() function.
printf(str(2) + " " + str(4))
The output will be: 2 4
WOW!!!
It’s pretty long time ago
Now, In python 3.x it will be pretty easy
code:
for i in range(20):
print('a',end='') # here end variable will clarify what you want in
# end of the code
output:
aaaaaaaaaaaaaaaaaaaa
More about print() function
print(value1,value2,value3,sep='-',end='n',file=sys.stdout,flush=False)
Here:
value1,value2,value3
you can print multiple values using commas
sep = '-'
3 values will be separated by ‘-‘ character
you can use any character instead of that even string like sep=’@’ or sep=’good’
end='n'
by default print function put ‘n’ charater at the end of output
but you can use any character or string by changing end variale value
like end=’$’ or end=’.’ or end=’Hello’
file=sys.stdout
this is a default value, system standard output
using this argument you can create a output file stream like
print("I am a Programmer", file=open("output.txt", "w"))
by this code you will create a file named output.txt where your output
I am a Programmer will be stored
flush = False
It’s a default value
using flush=True you can forcibly flush the stream
as simple as that
def printSleeping():
sleep = "I'm sleeping"
v = ""
for i in sleep:
v += i
system('cls')
print v
time.sleep(0.02)
this is really simple
for python 3+ versions you only have to write the following codes
for i in range(20):
print('a',end='')
just convert the loop to the following codes, you don’t have to worry about other things
in python 2, add (,) after print and it will act as end=” in python 3. But for space in between, you are still off to use future version of the print.
for x in ['a','b','c','d']:
print(x),
I have this code:
>>> for i in xrange(20):
... print 'a',
...
a a a a a a a a a a a a a a a a a a a a
I want to output 'a', without ' ' like this:
aaaaaaaaaaaaaaaaaaaa
Is it possible?
without what?
do you mean
>>> print 'a' * 20
aaaaaaaaaaaaaaaaaaaa
?
You can suppress the space by printing an empty string to stdout between the print statements.
>>> import sys
>>> for i in range(20):
... print 'a',
... sys.stdout.write('')
...
aaaaaaaaaaaaaaaaaaaa
However, a cleaner solution is to first build the entire string you’d like to print and then output it with a single print statement.
You could print a backspace character ('b'):
for i in xrange(20):
print 'ba',
result:
aaaaaaaaaaaaaaaaaaaa
From PEP 3105: print As a Function in the What’s New in Python 2.6 document:
>>> from __future__ import print_function
>>> print('a', end='')
Obviously that only works with python 3.0 or higher (or 2.6+ with a from __future__ import print_function at the beginning). The print statement was removed and became the print() function by default in Python 3.0.
Python 3.x:
for i in range(20):
print('a', end='')
Python 2.6 or 2.7:
from __future__ import print_function
for i in xrange(20):
print('a', end='')
There are a number of ways of achieving your result. If you’re just wanting a solution for your case, use string multiplication as @Ant mentions. This is only going to work if each of your print statements prints the same string. Note that it works for multiplication of any length string (e.g. 'foo' * 20 works).
>>> print 'a' * 20
aaaaaaaaaaaaaaaaaaaa
If you want to do this in general, build up a string and then print it once. This will consume a bit of memory for the string, but only make a single call to print. Note that string concatenation using += is now linear in the size of the string you’re concatenating so this will be fast.
>>> for i in xrange(20):
... s += 'a'
...
>>> print s
aaaaaaaaaaaaaaaaaaaa
Or you can do it more directly using sys.stdout.write(), which print is a wrapper around. This will write only the raw string you give it, without any formatting. Note that no newline is printed even at the end of the 20 as.
>>> import sys
>>> for i in xrange(20):
... sys.stdout.write('a')
...
aaaaaaaaaaaaaaaaaaaa>>>
Python 3 changes the print statement into a print() function, which allows you to set an end parameter. You can use it in >=2.6 by importing from __future__. I’d avoid this in any serious 2.x code though, as it will be a little confusing for those who have never used 3.x. However, it should give you a taste of some of the goodness 3.x brings.
>>> from __future__ import print_function
>>> for i in xrange(20):
... print('a', end='')
...
aaaaaaaaaaaaaaaaaaaa>>>
If you want them to show up one at a time, you can do this:
import time
import sys
for i in range(20):
sys.stdout.write('a')
sys.stdout.flush()
time.sleep(0.5)
sys.stdout.flush() is necessary to force the character to be written each time the loop is run.
Just as a side note:
Printing is O(1) but building a string and then printing is O(n), where n is the total number of characters in the string. So yes, while building the string is “cleaner”, it’s not the most efficient method of doing so.
The way I would do it is as follows:
from sys import stdout
printf = stdout.write
Now you have a “print function” that prints out any string you give it without returning the new line character each time.
printf("Hello,")
printf("World!")
The output will be: Hello, World!
However, if you want to print integers, floats, or other non-string values, you’ll have to convert them to a string with the str() function.
printf(str(2) + " " + str(4))
The output will be: 2 4
WOW!!!
It’s pretty long time ago
Now, In python 3.x it will be pretty easy
code:
for i in range(20):
print('a',end='') # here end variable will clarify what you want in
# end of the code
output:
aaaaaaaaaaaaaaaaaaaa
More about print() function
print(value1,value2,value3,sep='-',end='n',file=sys.stdout,flush=False)
Here:
value1,value2,value3
you can print multiple values using commas
sep = '-'
3 values will be separated by ‘-‘ character
you can use any character instead of that even string like sep=’@’ or sep=’good’
end='n'
by default print function put ‘n’ charater at the end of output
but you can use any character or string by changing end variale value
like end=’$’ or end=’.’ or end=’Hello’
file=sys.stdout
this is a default value, system standard output
using this argument you can create a output file stream like
print("I am a Programmer", file=open("output.txt", "w"))
by this code you will create a file named output.txt where your output
I am a Programmer will be stored
flush = False
It’s a default value
using flush=True you can forcibly flush the stream
as simple as that
def printSleeping():
sleep = "I'm sleeping"
v = ""
for i in sleep:
v += i
system('cls')
print v
time.sleep(0.02)
this is really simple
for python 3+ versions you only have to write the following codes
for i in range(20):
print('a',end='')
just convert the loop to the following codes, you don’t have to worry about other things
in python 2, add (,) after print and it will act as end=” in python 3. But for space in between, you are still off to use future version of the print.
for x in ['a','b','c','d']:
print(x),