Add a couple of exercises

Author: abregman

README.md

@@ -4,8 +4,17 @@
 
 |Name|Objective & Instructions|Solution|Comments|
 |--------|--------|------|----|
-| Hello World! | [Exercise](exercises/hello_world/hello_world.md) | [Solution](solutions/hello_world/hello_world.md) | |
-| 22 times | [Exercise](exercises/hello_world/22_times.md) | [Solution](solutions/hello_world/22_times.md) | |
+| Hello World! | [Exercise](exercises/hello_world/hello_world.md) | | |
+| 22 times | [Exercise](exercises/hello_world/22_times.md) | | |
+| Length | [Exercise](exercises/hello_world/length.md) | | |
+
+## Data Types
+
+|Name|Objective & Instructions|Solution|Comments|
+|--------|--------|------|----|
+| Data Types? I know a few | [Exercise](exercises/data_types/I_know_a_few.md) | [Solution](solutions/exceptions/I_know_a_few.md) | |
+| Choose a Data Type - level 1 | [Exercise](exercises/data_types/choose_datatype_level_1.md) | [Solution](solutions/data_types/choose_datatype_level_1.md) | |
+| Choose a Data Type - level 2 | [Exercise](exercises/data_types/choose_datatype_level_2.md) | [Solution](solutions/data_types/choose_datatype_level_2.md) | |
 
 ## Loops
 
@@ -31,3 +40,17 @@
 |Name|Objective & Instructions|Solution|Comments|
 |--------|--------|------|----|
 | Dividing by Zero | [Exercise](exercises/exceptions/divide_by_zero.md) | [Solution](solutions/exceptions/divide_by_zero.md) | |
+
+## Files
+
+|Name|Objective & Instructions|Solution|Comments|
+|--------|--------|------|----|
+| Read a File | [Exercise](exercises/files/read_file.md) | | |
+
+## Operating Systems
+
+|Name|Objective & Instructions|Solution|Comments|
+|--------|--------|------|----|
+| File exists | [Exercise](exercises/os/file_exists.md) | | |
+| Print all the files in a directory | [Exercise](exercises/os/print_all_files_in_dir.md) | | |
+

exercises/data_types/I_know_a_few.md

@@ -0,0 +1,3 @@
+## Data Types? I Know a Few
+
+Which data types are you familiar with?

exercises/data_types/choose_datatype_level_1.md

@@ -0,0 +1,7 @@
+## Choose a Data Type
+
+For each of the following scenarios, choose the data type you would use
+
+1. Storing the string "Hello World"
+2. Mapping between fruit names and their color
+3. A collection of numbers (sorted)

exercises/data_types/choose_datatype_level_2.md

@@ -0,0 +1,5 @@
+## Choose a Data Type - Level 2
+
+Choose a data type in each of the following scenarios:
+
+1. A class to represent a mushroom (name and whether it's poisonous) without custom methods

exercises/files/read_file.md

@@ -0,0 +1,3 @@
+## Read a File
+
+Write a code that will read a file and print all its content

exercises/hello_world/length.md

@@ -0,0 +1,6 @@
+## Length
+
+1. How to print the length of the string 'abcd' ?
+2. How to print the length of the variable x (x is the list [5, 30 ,2]) ?
+3. What would be the length of following dictionary {'x': 3, 'y': 3} ?
+4. What would be the length of the tuple ('x', 'y') ?

exercises/loops/refactor_1.md

@@ -5,10 +5,10 @@ Refactor the following code
 ```python
 from collections import namedtuple
 
-Mushroom = collections.nametuple('Mushroom', ['name', 'poisonous'])
+Mushroom = namedtuple('Mushroom', ['name', 'poisonous'])
 
-mushrooms = [Mushroom('Portabello', false), Mushroom('Oyster', false),
-             Mushroom('Death Cap', true)]
+mushrooms = [Mushroom('Portabello', False), Mushroom('Oyster', False),
+             Mushroom('Death Cap', True)]
 i = 0
 
 for mushroom in mushrooms:

exercises/os/file_exists.md

@@ -0,0 +1,3 @@
+## File Exists
+
+For a given file, check if the file exists

exercises/os/print_all_files_in_dir.md

@@ -0,0 +1,3 @@
+## Print all the files in a directory
+
+Without using `os.walk` or `os.tree`, print all the files in a given directory (including any nested directories)

solutions/data_types/I_know_a_few.md

@@ -0,0 +1,18 @@
+## Data Types? I know a few
+
+The built-in data types:
+  * dict: {'x': 1, 'y': 2}
+  * list: [1, 2]
+  * set: {'x', 'y'}
+  * frozenset: {'x', 'y'}
+  * str: 'x, y'
+  * tuple: ('x', 'y')
+
+There are also modules which are part of the standard library and provide their own data types:
+  * datetime
+  * collections.namedtuple
+  * collections.abc
+  * bisect
+  ...
+
+The list is quite long and be seen fully [here](https://docs.python.org/3/library/datatypes.html)

solutions/data_types/choose_datatype_level_1.md

@@ -0,0 +1,7 @@
+## Choose a Data Type
+
+For each of the following scenarios, choose the data type you would use
+
+1. Storing the string "Hello World" - str
+2. Mapping between fruit names and their color - dict: {'apple': 'red'}
+3. A collection of numbers (sorted) - list: [1, 5, 6]

solutions/data_types/choose_datatype_level_2.md

@@ -0,0 +1,7 @@
+## Choose a Data Type - Level 2
+
+Choose a data type in each of the following scenarios:
+
+1. A class to represent a mushroom (name and whether it's poisonous) without custom methods
+
+namedtuple: `Mushroom = collection.namedtuple('Mushroom', ['Oyster', False])`