#open & close
f = open("test.txt",'r')
i = 1
for line in f:
 ? ?print(i,' ===> ',line)
 ? ?i = i + 1
f.close()

#read 函數(shù)一次性讀取文件的全部?jī)?nèi)容，以單個(gè)字符串形式返回全部文件
f = open("test.txt",'r')
contents = f.read()
for word in contents:
 ? ?print(word)
f.close()

#realine函數(shù)逐行讀取
f = open("test.txt",'r')
line1 = f.readline()
print(line1)
line2 = f.readline()
print(line2)
for l in f:#從readline結(jié)束的位置開始訪問(wèn)，有一個(gè)指針
 ? ?print(l)
f.close()

#readlines 一次性讀取多行，返回一個(gè)列表，每個(gè)元素是一行
f = open("test.txt",'r')
line = f.readlines()
print(line)
f.close()

#文件寫入write writeline writelines
#r只讀 ? w只寫 ? a只寫（追加）
#r+讀寫文件開始處 ? w+讀寫文件開始處 ? a+讀寫文件末尾
#wb ?rb ? 是讀寫二進(jìn)制文件專用的
s = 'welcome\nchina'
f = open("test.txt",'w+')
f.write(s)
lines = f.readlines()
print(lines)

#文件路徑
import os
print(os.getcwd())
path = "./code/tmp.txt" ? #當(dāng)前目錄下的code文件夾下的tmp
path = "../tmp.txt" ? #當(dāng)前目錄的父目錄文件夾下的tmp

#捕獲異常
try:
 ? ?f = open("tedst.txt",'r')
 ? ?for line in f:
 ? ? ? ?pass
except:
 ? ?print("file don't exist")

#pickle模塊
import pickle
f = open('test.pkl','wb')
d = "Tsinghua"
pickle.dump(d,f)
f.close()
newf = open('test.pkl','rb')
newt = pickle.load(newf)
print(newt)

#json模塊
import json
f = open('test.json','w')
d = "Tsinghua"
json.dump(d,f)
f.close()
newf = open('test.json','rb')
newt = json.load(newf)
print(newt)

#csv模塊，逗號(hào)分隔值文件，可以將excel文件保存為CSV格式，進(jìn)行逗號(hào)分隔
import csv
fcsv = open('test.csv','rU')
allcontent = []
csvobj = csv.reader(fcsv)
for l in csvobj:
 ? ?allcontent.append(l)
for l in allcontent:
 ? ?if l[0] != 'name':
 ? ? ? ?l.append(int(l[1])*int(l[2]))
 ? ?else:
 ? ? ? ?l.append('乘積')
with open('test.csv','w') as writeobj:
 ? ?writer = csv.writer(writeobj)
 ? ?for r in allcontent:
 ? ? ? ?writer.writerow(r)
with open('test.csv','r') as readobj:
 ? ?csvread = csv.reader(readobj)
 ? ?for l in csvread:
 ? ? ? ?print(l)