Question

I need a lot of questions for practicing writing and reading file in Python program to study for my final, but I couldn't find it anywhere. Help me, please! :(

And also, I barely understand file in Python, so the questions need to be from easy and moderate, please!

Thanks for helping!

Answer 1

when we want handle large amount of data we used files.

we store the data into files we perform operations on the file.

we take inputs in many ways in python one way is taking input from user by using input() method.

the another way take input from files.files are many types.

some are text files some are csv files csv files are each column separated with comma.

so based on the file type we can perform operation.

file is a object it contain many methods.

open()=This method is uses to open a file and which kind of mode we can pass as a second argument.

modes are very important when we dealing with file.

mode type->

r->when we use r mode we only do read the data from file.

w->when we use write mode we only able to write the data into file.we didn't able to read the data.

r+->when we used r+ mode we did able to read and write the data into file

w+->when we used w+ write and read the data from file

a->append the data into file.append is most important mode in files because when we open a file in write mode.the file contain some text.if we used write mode the file contain data override and replace with what we type.

so we lost important data from file.if we used "a" mode we can simply data append to file data.

the data didn't override.after the data our producing data will append to the file.

x->this mode much not import just if the file doesn't exist we can create a file using x mode.

read() method:

this method is used to read the data from file and gives entire file as a string.

readlines() method:

this method used to read the data from file and each line make a list object

write() method:

this method used to write the data into file.

we see one by one withh examples.

fiirst we deal with open and read:

open the file and read the data from file.

i have file namana.txt it contain iam HomeworkLib expert

here we used mode is "r" because we read the data from file.

we must remember one thing when we open a file after completion file operation we must close the file.

namana.txt

iam HomeworkLib expert

#output:

python source code file and text file must in same directory.if the file in other directory we must declare the full path of the file,

next write the data into file when we used write method automatically file created if the file doesnot exist on directory.

but when we read operation the file must be there.

write the data into file.

so we used write the data into file so we used write mode.

source code:

#output namana1.txt file is:

here we see why we used append mode:

namana1.txt contain data "iam vishnu vardhan"

so i want add his age.i used write method what will happend we see

source code:

#output:

"iam vishnu vardhan" replace with age=34 so this is override of data.that mean past file data erased and new data only update into file.so that's why based on condition we are going with append mode.it doesnpt override the data.

ex:

here we used append mode "a" and we append the data year=2019.

lets see the output.

source code:

#output:

based on the data output we can perform any operation..

#if you have any doubts comment below..if you like give thums up.....