Python Shelve- Day 12(1 day later)

#shelve are same like dictionary,except that shelve can be used while #dealing with extremely large dictionary,dictionary will be handled in memory, #where as shelve will handle in a separate file #key points to note in shelve is that , the file with extension .db(or dit,bak,dat) ## will be created, #in dictionary since it is in memory,even if there is any mistake like type we can #change it immediately by changing the typo ,where as in shelve we have to #delete that key combination

  
import shelve

# with shelve.open("D:/WORK/2018/February/22-02-2018-Thursday/shelvetest1")as fruit:
#     fruit = {"orange":"its a fruit which is orange in color",
#               "apple":"good for health"}
#     print(fruit)
#     print(fruit["orange"])
# print("="*40)
# print(fruit["orange"])
# print(fruit)

with shelve.open("D:/WORK/2018/February/22-02-2018-Thursday/shelvetest2")as fruit:
    fruit["orange"]="its a fruit which is orange in color"
    fruit["apple"]="good for health"
print(fruit)
print("="*40)
#the below peice of code will throw an error
# print(fruit["orange"])


with shelve.open("D:/WORK/2018/February/22-02-2018-Thursday/shelvebike1")as bike:
    bike["name"]="tvs"
    bike["engine_cc"]="250 cc"
    #even if removed and executes the below code it will be saved
    #in the first run and remains there,which is not the case if
    #it is normal dictionary
    # bike["engin_cc"]="250 cc"
    bike["model"]="victor"
    print(bike)
    for i in bike:
        print(i)
        print(bike[i])
###############################################################################
import shelve

with shelve.open("D:/WORK/2018/February/22-02-2018-Thursday/shelvebike1")as bike:
    bike["name"]="tvs"
    bike["engine_cc"]="250 cc"
    #even if removed and executes the below code it will be saved
    #in the first run and remains there,which is not the case if
    #it is normal dictionary
    # bike["engin_cc"]="250 cc"
    #we can delete that key using,it has to be run one time only
    # del bike["engin_cc"]
    bike["model"]="victor"
    print(bike)
    for i in bike:
        print(i)
        print(bike[i])

 

Python Read Write File,Binary Read Write File - Day 11(2 days later)

*Read Write File

  
# #this shows how to open and read contents from the file
# samplefilevar = open("D:/WORK/2018\February/20-02-2018-Tuesday/pythonsamplereadfile.txt",'r')
# for linevar in samplefilevar:
#     print (linevar)
# samplefilevar.close()
#
# print("===="*20)
# #print only the lines containing the specific word
# samplefilevar = open("D:/WORK/2018\February/20-02-2018-Tuesday/pythonsamplereadfile.txt",'r')
# for linevar in samplefilevar:
#     if "file" in linevar.lower():
#         print (linevar,end = '')
# samplefilevar.close()
# print("===="*20)
# #using with keyword will automatically close the file,we dont need to
# #use the separate close statement
#
# with open("D:/WORK/2018\February/20-02-2018-Tuesday/pythonsamplereadfile.txt",'r')as var2:
#     for line in var2:
#         #end = '' is used to avoid using the extra empty line
#         print(line,end='')

# with open("D:/WORK/2018\February/20-02-2018-Tuesday/pythonsamplereadfile.txt",'r')as var2:
#     line =var2.readline()
#     print(line)
# with open("D:/WORK/2018\February/20-02-2018-Tuesday/pythonsamplereadfile.txt",'r')as var2:
#     #readlines will read all lines and piut it into list,so it is better to use readline,
#     #since the readlines will read the entire file in memory,where as readline will
#     #go row by row
#     lines =var2.readlines()
#     print(lines)
#
# for line1 in lines:
#     print(line1,end='')

#write contents to a file
# cities = ["Delhi","Bombay","Chennai"]
#
# with open("D:/WORK/2018\February/20-02-2018-Tuesday/pythonsamplewritefile1.txt",'w')as var2:
#     for city in cities:
#         print(city,file=var2)
#
# with open("D:/WORK/2018\February/20-02-2018-Tuesday/pythonsamplewritefile1.txt",'r')as var3:
#     cities = var3.readlines()
# print(cities)
#
# #strip functions strips the character that is present at the end or beginning 
#,but not the middle
# for city in cities:
#     print(city)
#     print(city.strip("\n"))
#
# cityvar1 = []
# with open("D:/WORK/2018\February/20-02-2018-Tuesday/pythonsamplewritefile1.txt",'r')as var3:
#     cities = var3.readlines()
#     for city in cities:
#         cityvar1.append(city)
#
# print(cityvar1)
#
# cityvar2 = []
# with open("D:/WORK/2018\February/20-02-2018-Tuesday/pythonsamplewritefile1.txt",'r')as var3:
#     cities = var3.readlines()
#     for city in cities:
#         cityvar2.append(city.strip("\n"))
#
# print(cityvar2)
#
# strvar1 = "testing"
# print(strvar1.strip("s"))
# print(strvar1.strip("g"))
# #below will remove t at the beginning not the st at the middle
# print(strvar1.strip("st"))


#tuples to file
# albumtuplevar2 = "muthu","rahman",2000,(1,"oruvan oruvan"),(2,"kuluvall"),(3,"vidukathaya")
# print(albumtuplevar2)
# title,composer,year,track1,track2,track3 =albumtuplevar2
# print(title)
# print(composer)
# print(year)
# print(track1)
# print(track2)
# print(track3)
#
# with open("D:/WORK/2018\February/20-02-2018-Tuesday/pythonsamplewritefile2.txt",'w')as var2:
#     print(albumtuplevar2,file=var2)

with open("D:/WORK/2018\February/20-02-2018-Tuesday/pythonsamplewritefile2.txt",'r')as var3:
    var4 = var3.readlines()
print(var4)
print(var4)
######################################################################
#appending the tables to the existing file
#if we use the mode 'a',it will append it ,if we use the mode 'w',it will overwrite the file
#our challenge is to print like
#1 times 2 is 2
#2 times 2 is 4
#....
#likewise till 13 table

with open("D:/WORK/2018/February/20-02-2018-Tuesday/pythonwritefile3.txt",'w')as tables:
    for i in range(1,1000):
        for j in range(1,1000):
            print("{1} times {0} is {2}".format(i,j,i*j),file=tables)
        print("=="*20,file=tables)

#######################################################################
#We can use pickle ,instead of converting the binaty manually and reconverting
#while reading

import pickle

imedla = ('More Mayhem',
          'Imelda May',
          '2011',
          ((1,'Pulling the rug'),
           (2,'Psycho'),
           (3,'Mayhem'),
           (4,'Kentish Town Waltz')))

# with open("D:/WORK/2018/February/22-02-2018-Thursday/pythonwritefilebinary.pickle","wb") 
as pickle_file:
#     pickle.dump(imedla,pickle_file)

with open("D:/WORK/2018/February/22-02-2018-Thursday/pythonwritefilebinary.pickle","rb")
as imelda_pickled:
    imelda2 = pickle.load(imelda_pickled)

print(imelda_pickled)
print(imelda2)
album,artist,year,tracklist = imelda2
print (album)
print (artist)
print (year)
for track in tracklist:
    trackno,tracktile = track
    print("{0} : {1}".format(trackno,tracktile))
#########################################################################################
#storing multiple objects in the binary file and retrieving it in the same order
import pickle

imedla = ('More Mayhem',
          'Imelda May',
          '2011',
          ((1,'Pulling the rug'),
           (2,'Psycho'),
           (3,'Mayhem'),
           (4,'Kentish Town Waltz')))

even = list(range(0,10,2))
odd = list(range(1,10,2))

with open("D:/WORK/2018/February/22-02-2018-Thursday/pythonwritefilebinary2.pickle","wb") 
as pickle_file:
    pickle.dump(imedla,pickle_file,protocol=0)
    pickle.dump(even,pickle_file,protocol=0)
    pickle.dump(odd,pickle_file,protocol=0)
    pickle.dump(12345,pickle_file,protocol=0)
#to read the above objects we need to read it in the same order ie..tuples,list,variable

with open("D:/WORK/2018/February/22-02-2018-Thursday/pythonwritefilebinary2.pickle","rb")
as imelda_pickled:
    imelda2 = pickle.load(imelda_pickled)
    even_list = pickle.load(imelda_pickled)
    odd_list = pickle.load(imelda_pickled)
    x = pickle.load(imelda_pickled)

print(imelda_pickled)
print(imelda2)
album,artist,year,tracklist = imelda2
print (album)
print (artist)
print (year)
for track in tracklist:
    trackno,tracktile = track
    print("{0} : {1}".format(trackno,tracktile))

print("="*40)

for i in even_list:
    print(i)
print("="*40)
for i in odd_list:
    print(i)
print("="*40)
print(x)
###################################################################################