Python/C3/Getting-started-with-files/Gujarati - Revision history

Krupali at 11:25, 29 October 2013

2013-10-29T11:25:46Z

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Krupali at 10:36, 29 October 2013

2013-10-29T10:36:58Z

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Krupali at 07:28, 29 October 2013

2013-10-29T07:28:57Z

Krupali at 13:03, 28 October 2013

2013-10-28T13:03:23Z

Krupali: Created page with '{| border=1 !Timing !Narration |- | 0:00 | Hello Friends and Welcome to the tutorial on "Getting started with files". |- | 0:08 | At the end of this tutorial, you will be able t…'

2013-10-28T10:00:49Z

Created page with '{| border=1 !Timing !Narration |- | 0:00 | Hello Friends and Welcome to the tutorial on "Getting started with files". |- | 0:08 | At the end of this tutorial, you will be able t…'

New page

{| border=1
!Timing
!Narration
|-
| 0:00
| Hello Friends and Welcome to the tutorial on "Getting started with files".

|-
| 0:08
| At the end of this tutorial, you will be able to,

# Open a file.
# Read the contents of the file line by line.
# Read the entire content of file at once.
# Append the lines of a file to a list.
# Close the file.

|-
| 0:24
| Before beginning this tutorial,we would suggest you to complete the tutorial on "Getting started with Lists" and "Getting started with For".

|-
|0:34
|So now, open the terminal and start ipython

|-
|0:37
|So type ipython space hyphen pylab.

|-
| 0:46
| Let us first open the file, pendulum dot txt present in slash home slash fossee slash .

|-
|0:54
|So type f is equal to open within brackets and single quotes slash home slash fossee slash pendulum dot txt.

|-
| 1:11
| Here f is called a file object.

|-
| 1:14
| Let us type f on the terminal to see what it is.

|-
|1:17
|So type f and hit Enter.

|-
| 1:22
| The file object shows the filepath and mode of the file which is open.

|-
|1:27
| 'r' stand for read only mode and 'w' stands for write mode.

|-
|1:32
| As you can see, this file is open in read only mode.

|-
| 1:40
| We shall first learn to read the whole file into a single variable.

|-
|1:47
| We use the read method to read all the contents of the file into the variable,pend.

|-
|1:53
|So type pend is equal to f dot read closing brackets and hit Enter.

|-
| 2:02
| Now, let us see what pend contains, by typing Print space pend

|-
|2:11
| We can see that pend has all the data of the file.

|-
|2:15
|Type just pend to see more explicitly, what it contains.

|-
| 2:25
| So now, Pause the video here, try out the following exercise and resume the video.

|-
| 2:30
| Split the variable into a list, pend underscore list, of the lines in the file.

|-
| 2:40
| We use the function split lines to solve this problem.

|-
|2:44
|So type pend underscore list is equal to pend dot split lines closing brackets and hit Enter.

|-
| 3:05
| Now, let us learn to read the file line-by-line.

|-
| 3:11
| But, before that we will have to close the file, since the file has already been read till the end.

|-
|3:19
|Let us close the file opened into f.

|-
|3:24
|Then type f dot close closing brackets and hit Enter.

|-
| 3:29
| Again type f on the prompt to see what it contains.

|-
| 3:37
| Notice, that it now says the file has been closed.

|-
| 3:42
| It is a good programming practice to close any file objects that we have opened, after their job is done.

|-
| 3:50
| Let us, now move on to reading files line-by-line.

|-
| 3:54
| Pause the video here, try out the following exercise and resume the video.

|-
|4:00
|Re-open the file pendulum dot txt with f as the file object.

|-
| 4:05
| We just use the up arrow until we reach the open command and issue it again.Then hit Enter.

|-
| 4:18
| Now, to read the file line-by-line, we iterate over the file object line-by-line, using the for command.

|-
|4:27
|Let us iterate over the file line-wise and print each of the lines.

|-
|4:35
|So type in the command for space line space in space f colon , then , print line.

|-
| 4:47
|line is a variable, sometimes called the loop variable, and it is not a keyword.

|-
|4:53
|We could have used any other variable name, but line seems meaningful enough.

|-
| 5:00
| Instead of just printing the lines, let us append them to a list, line underscore list .

|-
|5:07
|We first initialize an empty list, line underscore list.

|-
|5:12
|for that type line underscore list is equal to square bracket and hit Enter.

|-
| 5:22
| Let us then read the file line-by-line and then append each of the lines to the list.

|-
|5:30
|We could, as usual close the file using f.close and re-open it.

|-
|5:36
|But, this time, let's leave alone the file object f and directly open the file within the for statement.

|-
|5:43
| This will save us the trouble of closing the file, each time we open it.

|-
|5:49
|So type for line in open within brackets and single quotes slash home slash fossee slash pendulum dot txt colon

line underscore list dot append within brackets line,Hit Enter.

|-
| 6:22
| Let us see what line underscore list contains.

|-
|6:26
|so type line underscore list and hit Enter.

|-
| 6:33
| Notice that line_list is a list of the lines in the file, along with the newline characters.

|-
| 6:42
| If you noticed, pend underscore list did not contain the newline characters, because the string pend was split on the newline characters.

|-
|6:52
|We can strip out the newline characters from the lines by using some string methods which we shall look in the further tutorial on strings.

|-
|7:04
| So now, This brings us to the end of this tutorial. Lets revise what we have learnt,

|-
|7:12
|1. Open and close files using the open and close functions respectively.

|-
|7:17
|2. Read the data in the files as a whole,by using the read function.

|-
|7:22
|3. Read the data in the files line by line by iterating over the file object using the for loop.

|-
|7:31
|and finally Append the lines of a file to a list using the append function within the for loop.

|-
| 7:38
| Here are some self assessment questions for you

|-
|7:42
|1. The open function returns a

|-
|7:46
| string

|-
|7:48
| list

|-
|7:49
| file object

|-
|7:50
| function

|-
|7:52
|2. What does the function splitlines() do.

|-
|7:57
| Displays the data as strings,all in a line

|-
|8:01
| Displays the data line by line as strings

|-
|8:03
| Displays the data line by line but not as strings

|-
| 8:07
| So now,let us look at the answers,

|-
|8:09
|1.The function open , returns a file object.

|-
|8:15
|2. The function splitlines displays the data line by line as strings.

|-
| 8:21
| So we hope you have enjoyed this tutorial and found it useful.

|-
|8:27
|Thank you!

|}

@@ Line 11: / Line 11: @@
 # ફાઈલ ખોલવું.
-# Read the contents of the file line by line.
+# ફાઇલના કન્ટેનટ્સ લાઈન થી લાઈન વાંચો.
-# Read the entire content of file at once.
+# એક જ સમયે ફાઇલના સમગ્ર કન્ટેનટ્સ વાંચો.
-# Append the lines of a file to a list.
+# ફાઇલ ની લાઈન લીસ્ટમાં ઉમેરો.
-# Close the file.
+# ફાઈલ બંધ કરો.
-−
 |-
 | 0:24
-| Before beginning this tutorial,we would suggest you to complete the tutorial on "Getting started with Lists" and "Getting started with For".
+| આ ટ્યુટોરીયલ શરૂ કરો તે પહેલાં, અમે તમને "Getting started with Lists" અને "Getting started with For" પરના ટ્યુટોરીયલ જોવા માટે સૂચિત કરીશું.
 |-
 |0:34
-|So now, open the terminal and start ipython
+|તો ટર્મિનલ ખોલો અને ipython શરુ કરો.
 |-
 |0:37
-|So type ipython space hyphen pylab.
+|તો ટાઇપ કરો, ipython સ્પેસ હાયફન pylab.
 |-
 |  0:46
-| Let us first open the file, pendulum dot txt present in slash home slash fossee slash .
+| ચાલો પ્રથમ pendulum dot txt ફાઈલ ખોલીએ, જે slash home slash fossee slash માં હાજર છે.
 |-
 |0:54
-|So type f is equal to open within brackets and single quotes slash home slash fossee slash pendulum dot txt.
+|તો ટાઇપ કરો, f ઇકવલ ટુ open કૌશ અંદર અને સિંગલ અવતરણ ચિહ્નમાં slash home slash fossee slash pendulum dot txt.
 |-
 |  1:11
-| Here f  is called a file object.
+| અહીં f એ ફાઈલ ઓબ્જેક્ટ તરીકે ઓળખાય છે.
 |-
 | 1:14
-| Let us type f  on the terminal to see what it is.
+| ચાલો f શું છે તે જાણવા માટે ટર્મિનલ પર f ટાઇપ કરીએ.
 |-
 |1:17
-|So type f and hit Enter.
+|તો f ટાઇપ કરો અને એન્ટર ડબાઓ.
 |-
 | 1:22
-| The file object shows the filepath and mode of the file which is open.
+|ફાઈલ ઓબ્જેક્ટ ફાઈલ પાથ અને ફાઈલ નો મોડ દર્શાવે છે જે open છે.
 |-
 |1:27
 | 'r' stand for read only mode and 'w' stands for write mode.
 |-

@@ Line 4: / Line 4: @@
 |-
 | 0:00
-| Hello Friends and Welcome to the tutorial on "Getting started with files".
+| હેલો મિત્રો, "ફાઈલો સાથે શરૂઆત" કરવા પરના ટ્યુટોરીયલમાં સ્વાગત છે.
 |-
 | 0:08
-| At the end of this tutorial, you will be able to,
+| આ ટ્યુટોરીયલના અંતે, તમે નીચે આપેલ કરવા માટે સમક્ષ હશો,
-# Open a file.
+# ફાઈલ ખોલવું.
 # Read the contents of the file line by line.
 # Read the entire content of file at once.