# HG changeset patch # User Puneeth Chaganti # Date 1287478562 -19800 # Node ID c65d0d9fc0c8d619f9739567897e28006a3a1986 # Parent c4cb18752adefedba4c1cc1dadaac869d0589a93 Reviewed Basic datatypes LO. diff -r c4cb18752ade -r c65d0d9fc0c8 basic-data-type/questions.rst --- a/basic-data-type/questions.rst Thu Oct 14 14:11:54 2010 +0530 +++ b/basic-data-type/questions.rst Tue Oct 19 14:26:02 2010 +0530 @@ -3,6 +3,9 @@ .. A mininum of 8 questions here (along with answers) +.. #[Puneeth: ``Answer: Any size.``. Demarcate the answer from the +.. question.] + 1. How large can an integer in Python be? Any Size. @@ -18,11 +21,10 @@ c= 3.2 + 4.6j - 3. Look at the following piece of code :: - In []: f or t - Out[]:True + In []: f or t + Out[]:True What can you comment about the data type of f and t ? @@ -33,12 +35,15 @@ 5. Look at the following sequence :: - In []:t=true - NameError: name 'true' is not defined + In []:t=true + NameError: name 'true' is not defined What might be the reason for error here? - In this scenario , it seems the programmer wanted to create a variable t with the boolean value True with a capital T. Since no variable by the name true(small t) is known to the interpreter it gives a NameError. + In this scenario , it seems the programmer wanted to create a + variable t with the boolean value True with a capital T. Since no + variable by the name true(small t) is known to the interpreter it + gives a NameError. 6. Put the following string in a variable quotation. @@ -48,11 +53,14 @@ 7. Given a tuple :: - tup=(7,4,2,1,3,6,5,8) - tup[-2] + tup=(7,4,2,1,3,6,5,8) + tup[-2] 5 +.. #[Puneeth: ``Answer: Any size.``. Demarcate the answer from the +.. question.] + 8. What is the syntax for checking containership in Python?:: element in sequence @@ -78,6 +86,9 @@ 1. Given two lists for example, list1=[1,2,3,4] and list2=[1,2,3,4,5,6,7] write a program to remove one list from the other. +.. #[Puneeth: dependency LOs?] #. Write a program to check if a string is palindrome? +.. #[Puneeth: comparison has not been taught, has it? does this depend +.. on any other LO?] diff -r c4cb18752ade -r c65d0d9fc0c8 basic-data-type/script.rst --- a/basic-data-type/script.rst Thu Oct 14 14:11:54 2010 +0530 +++ b/basic-data-type/script.rst Tue Oct 19 14:26:02 2010 +0530 @@ -13,16 +13,24 @@ Internal Reviewer : External Reviewer : Checklist OK? : [2010-10-05] -Hello friends and welcome to the tutorial on Basic Data types and operators in Python. + +.. #[Puneeth: Fill in pre-requisites.] + +Hello friends and welcome to the tutorial on Basic Data types and operators +in Python. + {{{ Show the slide containing title }}} {{{ Show the slide containing the outline slide }}} -In this tutorial, we shall look at:: +In this tutorial, we shall look at * Datatypes in Python * Operators in Python +.. #[Puneeth: Use double colon only for code blocks.] +.. #[Puneeth: include more details in the outline.] + with a little hands-on on how they can be applied to the different data types. @@ -34,9 +42,15 @@ These are: - * Integers - * float and - * Complex + * int for integers + * float for floating point numbers and + * complex for complex numbers + +.. #[Puneeth: Changed to int, float and complex.] + +.. #[Puneeth: Loss of consistency. You talk of built-in data types, but +.. then you were calling them integers, floats and complex. Clean up +.. required.] Lets first talk about integers. :: @@ -44,8 +58,7 @@ a -Thats it, there we have our first integer variable a. - +Now, we have our first integer variable a. If we now see :: @@ -53,51 +66,58 @@ type(a) -This means that a is a type of int. Being an int data structure -in python means that there are various functions that this variable -has to manipulate it different ways. You can explore these by doing, +This means that a is a type of int. Being an int data structure in python +means that there are various functions that this variable has to manipulate +it different ways. You can explore these by doing, a. - +.. #[Puneeth: Why are we suddenly talking of limits? +.. Something like this would be better. +.. int data-type can hold integers of any size. for example - ] Lets see the limits of this int. b = 99999999999999999999 b -As you can see even when we put a value of 9 repeated 20 times -python did not complain. However when you asked python to print -the number again it put a capital L at the end. Now if you check -the type of this variable b, :: +As you can see even when we put a value of 9 repeated 20 times python did +not complain. However when you asked python to print the number again it +put a capital L at the end. Now if you check the type of this variable b, +:: type(b) -The reason for this is that python recognizes large integer numbers -by the data type long. However long type and integer type share there -functions and properties. +The reason for this is that python recognizes large integer numbers by the +data type long. However long type and integer type share there functions +and properties. -Lets now try out the second type in list called float. +.. #[Puneeth: again, the clean-up that I talked of above. Decide if you are +.. talking about the different type of numbers and the datatypes that are +.. used to represent them or if you are talking of the data-types and what +.. kind of numbers they represent. I think you should choose the former.] -Decimal numbers in python are recognized by the term float :: +Let us now look at the float data-type. + +Decimal numbers in python are represented by the float data-type :: p = 3.141592 p -If you notice the value of output of p isn't exactly equal to p. This -is because computer saves floating point values in a specific -format. There is always an aproximationation. This is why we should -never rely on equality of floating point numbers in a program. +If you notice the value of output of p isn't exactly equal to p. This is +because computer saves floating point values in a specific format. There is +always an aproximationation. This is why we should never rely on equality +of floating point numbers in a program. The last data type in the list is complex number :: c = 3.2+4.6j -as simple as that so essentialy its just a combination of two floats the -imaginary part being defined by j notation instead of i. Complex numbers have a lot of functions specific to them. -Lets check these :: +as simple as that so essentialy its just a combination of two floats the +imaginary part being defined by j notation instead of i. Complex numbers +have a lot of functions specific to them. Lets check these :: c. @@ -132,21 +152,26 @@ f and t - -The results are explanotary in themselves. +The results are self explanatory. -The usage of boolean brings us to an interesting question of precendence. -What if you want to apply one operator before another. +.. #[Puneeth: Why does booleans bring us to precedence? I don't see the +.. connection. Am I missing something?] + +The usage of boolean brings us to an interesting question of precedence. +What if you want to apply one operator before another. Well you can use parenthesis for precedence. -Lets write some piece of code to check this out. +Lets write some piece of code to check this out.:: In[]: a=False In[]: b=True In[]: c=True -To check how precedence changes with parenthesis. We will try two + +.. #[Puneeth: Consistency. In[]: is not present at other places.] + +To check how precedence changes with parenthesis, we will try two expressions and their evaluation. one :: @@ -162,19 +187,24 @@ gives the value False. -Lets now look at some operators available in Python to manipulate these data types. +Let's now look at some operators available in Python to manipulate +these data types. - +.. #[Puneeth: A mention of other operators would be good? Starting +.. with % and ** is a bit weird.] Python uses % for modulo operation :: 87 % 6 + and two stars for a exponent. :: 7**8 -In case one wishes to use the current value of variable in which the result is stored in the expression one can do that by putting the operator before `equal to`. :: +In case one wishes to use the current value of variable in which the result +is stored in the expression one can do that by putting the operator before +`equal to`. :: a=73 a*=34 @@ -191,22 +221,22 @@ a=a/23 - -Lets now discuss sequence data stypes in python. Sequence -datatypes are those in which elements are kept in a sequential -order. All the elements accessed using index. +Lets now discuss sequence data types in Python. Sequence data types +are those in which elements are kept in a sequential order. All the +elements accessed using index. +.. #[Puneeth: fix the last sentence - it sounds incomplete] -{{{ slide to for memory aid }}} +{{{ slide for memory aid }}} -The sequence datatypes in python are :: +The sequence datatypes in Python are :: * list * string * tuple -The list type is a container that holds a number of other -objects, in the given order. +The list type is a container that holds a number of other objects, in the +given order. We create our first list by typing :: @@ -214,19 +244,18 @@ num_list -Items enclosed in square brackets separated by comma -constitutes a list. +Items enclosed in square brackets separated by comma constitutes a list. -Lists can store data of any type in them. +Lists can store data of any type in them. We can have a list something like :: var_list = [1, 1.2, [1,2]] var_list - +.. #[Puneeth: some continuity, when jumping to strings?] -Now we will have a look at strings +Now we will have a look at strings type :: @@ -243,20 +272,24 @@ In[]: l="Double quote contain's single quote" In[]: m='''"Contain's both"''' +.. #[Puneeth: Contain's? That's not a word!] + Thus, single quotes are used as delimiters usually. -When a string contains a single quote, double quotes are used as delimiters. -When a string quote contains both single and double quotes, triple quotes are -used as delimiters. + +.. #[Puneeth: Thus?] + +When a string contains a single quote, double quotes are used as +delimiters. When a string quote contains both single and double quotes, +triple quotes are used as delimiters. The last in the list of sequence data types is tuple. -To create a tuple we use normal brackets '(' -unlike '[' for lists.:: +To create a tuple we use normal brackets '(' unlike '[' for lists.:: In[]: num_tuple = (1, 2, 3, 4, 5, 6, 7, 8) -Because of their sequential property there are certain functions and -operations we can apply to all of them. +Because of their sequential property there are certain functions and +operations we can apply to all of them. @@ -273,9 +306,9 @@ In[]: num_tuple[-3] -Indexing starts from 0 from left to right and from -1 when accessing -lists in reverse. Thus num_list[2] refers to the third element 3. -and greetings [-2] is the second element from the end , that is 'l'. +Indexing starts from 0 from left to right and from -1 when accessing lists +in reverse. Thus num_list[2] refers to the third element 3. and greetings +[-2] is the second element from the end , that is 'l'. @@ -287,7 +320,7 @@ In[]: t2=(3,4,6,7) In[]: num_tuple+t2 -len function gives the length :: +len function gives the length :: In[]: len(num_list) In[]: len(greeting_string) @@ -303,7 +336,7 @@ We see that it gives True and False accordingly. -Find maximum using max function and minimum using min:: +Find maximum using max function and minimum using min:: In[]: max(num_tuple) In[]: min(greeting_string) @@ -316,6 +349,8 @@ As a consequence of the order one we access a group of elements together. This is called slicing and striding. +.. #[Puneeth: Fix the sentence above. ] + First Slicing Given a list :: @@ -328,8 +363,9 @@ In[]: j[1:4] -The syntax for slicing is sequence variable name square bracket -first element index, colon, second element index.The last element however is notincluded in the resultant list:: +The syntax for slicing is, sequence variable name square bracket first +element index, colon, second element index. The last element however is not +included in the resultant list:: In[]: j[:4] @@ -337,6 +373,8 @@ If first element is left blank default is from beginning and if last element is left blank it means till the end. +:: + In[]: j[1:] In[]: j[:] @@ -351,12 +389,13 @@ new_num_list[1:8:2] [2, 4, 6, 8] -The colon two added in the end signifies all the alternate elements. This is why we call this concept -striding because we move through the list with a particular stride or step. The step in this example -being 2. +The colon two added in the end signifies all the alternate elements. This +is why we call this concept striding because we move through the list with +a particular stride or step. The step in this example being 2. -We have talked about many similar features of lists, strings and tuples. But there are many important -features in lists that differ from strings and tuples. Lets see this by example.:: +We have talked about many similar features of lists, strings and tuples. +But there are many important features in lists that differ from strings and +tuples. Lets see this by example.:: In[]: new_num_list[1]=9 In[]: greeting_string[1]='k' @@ -365,18 +404,21 @@ -As you can see while the first command executes with out a problem there is an error on the second one. +As you can see while the first command executes with out a problem there is +an error on the second one. Now lets try :: In[]: new_tuple[1]=5 -Its the same error. This is because strings and tuples share the property of being immutable. -We cannot change the value at a particular index just by assigning a new value at that position. +Its the same error. This is because strings and tuples share the property +of being immutable. We cannot change the value at a particular index just +by assigning a new value at that position. -We have looked at different types but we need to convert one data type into another. Well lets one -by one go through methods by which we can convert one data type to other: +We have looked at different types but we need to convert one data type into +another. Well lets one by one go through methods by which we can convert +one data type to other: We can convert all the number data types to one another :: @@ -384,21 +426,25 @@ d=float(i) d -Python has built in functions int, float and complex to convert one number type -data structure to another. +Python has built in functions int, float and complex to convert one number +type data structure to another. + +:: dec=2.34 dec_con=int(dec) dec_con -As you can see the decimal part of the number is simply stripped to get the integer.:: +As you can see the decimal part of the number is simply stripped to get the +integer.:: com=2.3+4.2j float(com) com -In case of complex number to floating point only the real value of complex number is taken. +In case of complex number to floating point only the real value of complex +number is taken. Similarly we can convert list to tuple and tuple to list :: @@ -407,15 +453,17 @@ tupl=(3,23,4,56) lst=list(tuple) -However string to list and list to string is an interesting problem. -Lets say we have a string :: +However converting a string to a list and a list to a string is an +interesting problem. Let's say we have a string :: In: somestring="Is there a way to split on these spaces." In: somestring.split() -This produces a list with the string split at whitespace. -similarly we can split on some other character. +This produces a list with the string split at whitespace. Similarly we can +split on some other character. + +:: In: otherstring="Tim,Amy,Stewy,Boss" @@ -464,4 +512,10 @@ Thank You. - +.. + Local Variables: + mode: rst + indent-tabs-mode: nil + sentence-end-double-space: nil + fill-column: 75 + End: diff -r c4cb18752ade -r c65d0d9fc0c8 basic-data-type/slides.org --- a/basic-data-type/slides.org Thu Oct 14 14:11:54 2010 +0530 +++ b/basic-data-type/slides.org Tue Oct 19 14:26:02 2010 +0530 @@ -67,6 +67,9 @@ ** Sorted(l) ** reversed(s) - + +* COMMENT +# [Puneeth: Where is the last slide?] +# [Puneeth: Why don't you use the template slides.org?]