Some small fixes

io.asciidoc

@@ -92,7 +92,7 @@ loop. This method returns a complete line including the newline character at the
 line. When an _empty_ string is returned, it means that we have reached the end of the file and we
 'break' out of the loop.
 
-In the end, we finally `close`the file.
+In the end, we finally `close` the file.
 
 Now, check the contents of the `poem.txt` file to confirm that the program has indeed written to
 and read from that file.

modules.asciidoc

@@ -264,7 +264,7 @@ A note on `del` - this statement is used to *delete* a variable/name and after t
 run, in this case `del a`, you can no longer access the variable `a` - it is as if it never existed
 before at all.
 
-Note that the `dir()` function works on *any* object. For example, run `dir('print')` to learn
+Note that the `dir()` function works on *any* object. For example, run `dir(print)` to learn
 about the attributes of the print function, or `dir(str)` for the attributes of the str class.
 
 There is also a http://docs.python.org/2/library/functions.html#vars[`vars()`] function which can

oop.asciidoc

@@ -192,7 +192,7 @@ include::programs/oop_objvar.txt[]
 .How It Works
 
 This is a long example but helps demonstrate the nature of class and object variables. Here,
-`population` belongs to the`Robot` class and hence is a class variable. The `name` variable belongs
+`population` belongs to the `Robot` class and hence is a class variable. The `name` variable belongs
 to the object (it is assigned using `self`) and hence is an object variable.
 
 Thus, we refer to the `population` class variable as `Robot.population` and not as

problem_solving.asciidoc

@@ -227,7 +227,7 @@ a `-v` option to make your program become more talkative or a `-q` to make it _q
 
 Another possible enhancement would be to allow extra files and directories to be passed to the
 script at the command line. We can get these names from the `sys.argv` list and we can add them to
-our `source` list using the `extend`method provided by the `list` class.
+our `source` list using the `extend` method provided by the `list` class.
 
 The most important refinement would be to not use the `os.system` way of creating archives and
 instead using the http://docs.python.org/2/library/zipfile.html[zipfile] or