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Good Input Template for Python Users for Quick and Fast Inputs
Автор thekushalghosh, история, 5 лет назад, По-английски

Hello Codeforces Community,

Actually all of the Python users over here would agree that "sometimes" we need to write a bit long for taking input in Python, and it is also slow.

That's why I made a good template for taking Quick And Fast Input, which I would like to share.

import sys
input = sys.stdin.readline

############ ---- Input Functions ---- ############
def inp():
    return(int(input()))
def inlt():
    return(list(map(int,input().split())))
def insr():
    s = input()
    return(list(s[:len(s) - 1]))
def invr():
    return(map(int,input().split()))

Just paste this template at the beginning of your Code.

It comprises of 4 functions :-

1) inp — For taking integer inputs.

2) inlt — For taking List inputs.

3) insr — For taking string inputs. Actually it returns a List of Characters, instead of a string, which is easier to use in Python, because in Python, Strings are Immutable.

4) invr — For taking space seperated integer variable inputs.

The input = sys.stdin.readline is actually for Faster Inputs, because line reading through System STDIN (Standard Input) is faster in Python.

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5 лет назад, # |
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This blog may be useful.

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»
5 лет назад, # |
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Thank You! This is so useful!

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4 года назад, # |
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Hi, I just want to ask when to use sys.stdin.readline, because once I used it and it gave me wrong output (WA) and when I removed it, my code was Accepted. Here are my submissions:

With sys.stdin.readline: 108547882 Without: 108548171

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    4 года назад, # ^ |
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    sys.stdin.readline also reads end of line "\n" character. See here vs here

    Also, note how does the blog takes string input in insr() function. It explicitly removes the last character.

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2 года назад, # |
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can anyone share the full template for Python please

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    2 года назад, # ^ |
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    I won't say my template is the best out there for Python. But I think it might be of some use to you. Sharing it below, I have made separate ones for both Codechef and Codeforces. Here you go. Hope you find it helpful :)

    # ENTER YOUR DETAILS HERE -------------------->
'''
        // -- Template by A_*_A -- //
                                            '''
#       <----------------------------------------

# ENTER YOUR CODE HERE  -------------------->
# sys.setrecursionlimit(1000)

''' #   0.7 sec average INTEST    -   best for Codechef
import atexit,io,os,sys
ss=io.BytesIO()
_write=ss.write
ss.write=lambda s:_write(s.encode())
atexit.register(lambda:os.write(1,ss.getvalue()))
y_in=open(0).read().split("\n")
def y_inf():
    for y_id in range(len(y_in)):
        yield y_id
y_ino=y_inf()
input=lambda:y_in[next(y_ino)]
# '''

''' #   1.1 sec average INTEST
import sys
input=sys.stdin.readline
# input=lambda:sys.stdin.readline().rstrip("\r\n")
# '''

# ''' # REGION FASTIO   1.7 sec average INTEST    -   best for Codeforces
import os,sys
from io import BytesIO,IOBase
BUFSIZ=8192
class FastIO(IOBase):
    newlines=0
    def __init__(self,file):
        self._fd=file.fileno()
        self.buffer=BytesIO()
        self.writable="n"in file.mode or "r" not in file.mode
        self.write=self.buffer.write if self.writable else None
    def read(self):
        while True:
            b=os.read(self._fd,max(os.fstat(self._fd).st_size,BUFSIZ))
            if not b:
                break
            ptr=self.buffer.tell()
            self.buffer.seek(0,2),self.buffer.write(b),self.buffer.seek(ptr)
        self.newlines=0
        return self.buffer.read()
    def readline(self):
        while self.newlines==0:
            b=os.read(self._fd,max(os.fstat(self._fd).st_size, BUFSIZ))
            self.newlines=b.count(b"\n")+(not b)
            ptr=self.buffer.tell()
            self.buffer.seek(0, 2),self.buffer.write(b),self.buffer.seek(ptr)
        self.newlines-=1
        return self.buffer.readline()
    def flush(self):
        if self.writable:
            os.write(self._fd,self.buffer.getvalue())
            self.buffer.truncate(0),self.buffer.seek(0)
class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer=FastIO(file)
        self.flush=self.buffer.flush
        self.writable=self.buffer.writable
        self.write=lambda s:self.buffer.write(s.encode("ascii"))
        self.read=lambda:self.buffer.read().decode("ascii")
        self.readline=lambda:self.buffer.readline().decode("ascii")
if sys.version_info[0]<3:
    sys.stdin,sys.stdout=FastIO(sys.stdin),FastIO(sys.stdout)
else:
    sys.stdin,sys.stdout=IOWrapper(sys.stdin),IOWrapper(sys.stdout)
input=lambda:sys.stdin.readline().rstrip("\r\n")
# END REGION '''

#   2.1 sec average INTEST
tcs = 1
# tcs = int(input())
for tc in range(tcs):
    print("Hello World!")

#       <----------------------------------------

# ENTER YOUR NOTES HERE -------------------->
'''
        // -- Template by A_*_A -- //
                                            '''
#       <----------------------------------------
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      2 года назад, # ^ |
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      @a_vantik_a Thanks! though I need to understand it all, looks daunting. Do you've a blog or something of that sort explaining it in chunks? Would be of big BIG help !

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        2 года назад, # ^ |
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        Hey, you are welcome. I am glad you found it helpful :) I have added commments to the code below, to make it a bit easy to understand. In case you want more reference or meaning about the code, you can simply google it. I referred a lot of blogs to come up with this FASTIO :)

        # ''' # 0.65 sec - NOTE: ONLY SEND STRINGS TO STDOUT
import atexit, io, os
inputt = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline   # read STDIN in 1 go
input = lambda: inputt()   # use for integer input
# input = lambda: inputt().decode().strip()   # use for string input
ss = io.BytesIO()
_write = ss.write
ss.write = lambda s: _write(s.encode())     # byte text optimization
atexit.register(lambda: os.write(1, ss.getvalue()))     # os.write is fast!!!
print=ss.write
# END REGION '''

        Have a good day, cheers!

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        2 года назад, # ^ |
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        I know using Python in Codeforces on a long term basis isn't really a good idea. But I am doing it for my own research reasons. Here is the whole list of FASTIO Comparisons I did for Python3, to come up with the best case for both Codechef and Codeforces, results were taken using best of 3 runs for each template. Hope you find it helpful :)


        # ''' # FASTIO  BEGINS 0.34 sec
# FASTIO  ENDS '''
import sys;k=int(sys.stdin.readline().split()[1]);sys.stdout.write('%d'%sum(1 for x in map(int,sys.stdin.buffer) if not x%k))

----------------------------------------------------------------

# ''' # FASTIO  BEGINS 0.37 sec
import sys
# FASTIO  ENDS '''
_, k = map(int, sys.stdin.readline().split())
count = sum(1 for x in map(int, sys.stdin.buffer) if not x % k)
sys.stdout.write(str(count))

----------------------------------------------------------------

# ''' # FASTIO  BEGINS 0.64 sec
import sys
input=sys.stdin.readline
# FASTIO  ENDS '''

y0, y1 = [int(x) for x in input().split()]
c = sum(not int(input()) % y1 for i in range(y0))
print(c)

----------------------------------------------------------------

# ''' # FASTIO  BEGINS 0.65 sec
import atexit, io, os
inputt = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline
input = lambda: inputt()   # int
# input = lambda: inputt().decode().strip()   # str
ss = io.BytesIO()
_write = ss.write
ss.write = lambda s: _write(s.encode())
atexit.register(lambda: os.write(1, ss.getvalue()))
# FASTIO  ENDS '''

y0, y1 = [int(x) for x in input().split()]
c = sum(not int(input()) % y1 for i in range(y0))
print(c)

----------------------------------------------------------------

# ''' # FASTIO  BEGINS 0.87 sec
import sys
input=lambda:sys.stdin.readline()
# FASTIO  ENDS '''

y0, y1 = [int(x) for x in input().split()]
c = sum(not int(input()) % y1 for i in range(y0))
print(c)

----------------------------------------------------------------

# ''' # FASTIO  BEGINS 0.94 sec
import atexit,io,os,sys
ss=io.BytesIO()
_write=ss.write
ss.write=lambda sett:_write(sett.encode())
atexit.register(lambda:os.write(1,ss.getvalue()))
y_in=open(0).read().split("\n")
def y_inf():
    for y_id in range(len(y_in)):
        yield y_id
y_ino=y_inf()
input=lambda:y_in[next(y_ino)]
# FASTIO  ENDS '''

y0, y1 = [int(x) for x in input().split()]
c = sum(not int(input()) % y1 for i in range(y0))
print(c)

----------------------------------------------------------------

# ''' # FASTIO  BEGINS 1.08 sec
import sys
input=lambda:sys.stdin.readline().rstrip("\r\n")
# FASTIO  ENDS '''

y0, y1 = [int(x) for x in input().split()]
c = sum(not int(input()) % y1 for i in range(y0))
print(c)

----------------------------------------------------------------

# ''' # FASTIO  BEGINS 1.8 sec
import os,sys
from io import BytesIO,IOBase
BUFSIZ=8192
class FastIO(IOBase):
    newlines=0
    def __init__(self,file):
        self._fd=file.fileno()
        self.buffer=BytesIO()
        self.writable="n"in file.mode or "r" not in file.mode
        self.write=self.buffer.write if self.writable else None
    def read(self):
        while True:
            b=os.read(self._fd,max(os.fstat(self._fd).st_size,BUFSIZ))
            if not b:
                break
            ptr=self.buffer.tell()
            self.buffer.seek(0,2),self.buffer.write(b),self.buffer.seek(ptr)
        self.newlines=0
        return self.buffer.read()
    def readline(self):
        while self.newlines==0:
            b=os.read(self._fd,max(os.fstat(self._fd).st_size, BUFSIZ))
            self.newlines=b.count(b"\n")+(not b)
            ptr=self.buffer.tell()
            self.buffer.seek(0, 2),self.buffer.write(b),self.buffer.seek(ptr)
        self.newlines-=1
        return self.buffer.readline()
    def flush(self):
        if self.writable:
            os.write(self._fd,self.buffer.getvalue())
            self.buffer.truncate(0),self.buffer.seek(0)
class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer=FastIO(file)
        self.flush=self.buffer.flush
        self.writable=self.buffer.writable
        self.write=lambda sett:self.buffer.write(sett.encode("ascii"))
        self.read=lambda:self.buffer.read().decode("ascii")
        self.readline=lambda:self.buffer.readline().decode("ascii")
if sys.version_info[0]<3:
    sys.stdin,sys.stdout=FastIO(sys.stdin),FastIO(sys.stdout)
else:
    sys.stdin,sys.stdout=IOWrapper(sys.stdin),IOWrapper(sys.stdout)
input=lambda:sys.stdin.readline().rstrip("\r\n")
# FASTIO  ENDS '''

y0, y1 = [int(x) for x in input().split()]
c = sum(not int(input()) % y1 for i in range(y0))
print(c)

----------------------------------------------------------------

# ''' # FASTIO  BEGINS 2.1 sec
# FASTIO  ENDS '''

y0, y1 = [int(x) for x in input().split()]
c = sum(not int(input()) % y1 for i in range(y0))
print(c)
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