100_questions_NLP_014

#!/usr/bin/env python
# -*- coding: utf-8 -*-
  
#Link: http://www.cl.ecei.tohoku.ac.jp/nlp100/
  
"""
hightemp.txt: http://www.cl.ecei.tohoku.ac.jp/nlp100/data/hightemp.txt
は，日本の最高気温の記録を「都道府県」「地点」「℃」「日」のタブ区切り形式で格納したファイルである．
以下の処理を行うプログラムを作成し，hightemp.txtを入力ファイルとして実行せよ．
Question 14:
14. 先頭からN行を出力
自然数Nをコマンドライン引数などの手段で受け取り，入力のうち先頭のN行だけを表示せよ．
確認にはheadコマンドを用いよ．
"""

import subprocess
import requests
import os

def download(url, dir, params={}):
  dl = requests.get(url, params=params)
  with file(dir, "wb") as f:
    f.write(dl.content)

from collections import deque

def readText(path, howMany = "all", direction = "forward"):
  #read all lines forwardly
  if howMany == "all" and direction == "forward":
    answer = ""
    with file(path, "r") as f:
      line = f.readline()
      while line:
        answer = answer + line
        line = f.readline()
    return answer
  
  #read all lines backwardly
  elif howMany == "all" and direction == "backward":
    answer = ""
    with file(path, "r") as f:
      line = f.readline()
      while line:
        answer = line + answer
        line = f.readline()
    return answer
    
  #read n-lines forwardly
  elif direction == "forward":
    count = 0
    answer = ""
    with file(path, "r") as f:
      line = f.readline()
      while line:
        if count >= int(howMany):
          break
        answer = answer + line
        line = f.readline()
        count = count + 1
    return answer

  #read n-lines backwardly
  elif direction == "backward":
    answer = deque()
    for i in xrange(howMany):
      answer.append("")
    with file(path, "r") as f:
      line = f.readline()
      while line:
        answer.append(line)
        answer.popleft()
        line = f.readline()
    answer.reverse()
    answer = list(answer)
    return "".join(answer)
    
  else:
    print("***********some options are weird***********")
    print("options of direction: forward, backward")
    print("howMany has to be number")
    print("********************************************")
    print("your direction is: " + direction)
    print("your howMany is: " + str(howMany))
    return False

def remove(path):
  if os.path.exists(path):
    os.remove(path)

def head(path, howMany):
  cmd = "head -n " + str(howMany) + " " + path
  with file("./head.txt", "wb") as f:
    subprocess.call(cmd, stdout=f, shell=True)
  with file("./head.txt", "r") as f:
    answer = readText("./head.txt")
    remove("./head.txt")
  return answer

#download hightemp.txt
download("http://www.cl.ecei.tohoku.ac.jp/nlp100/data/hightemp.txt","./hightemp.txt") if not os.path.exists("./hightemp.txt") else None

content = readText("./hightemp.txt")
lines = raw_input("how many lines would you like to see?: ")
readContent = readText("./hightemp.txt", howMany = int(lines))
headContent = head("./hightemp.txt", howMany = lines)

print("original file: \n" + content)
print("read " + str(lines) + "lines \n" + readContent)
print("head " + str(lines) + "lines \n" + headContent)