{"nbformat":4,"nbformat_minor":0,"metadata":{"kernelspec":{"display_name":"Python 3","language":"python","name":"python3"},"language_info":{"codemirror_mode":{"name":"ipython","version":3},"file_extension":".py","mimetype":"text/x-python","name":"python","nbconvert_exporter":"python","pygments_lexer":"ipython3","version":"3.6.5"},"colab":{"name":"01.07b.strings-and-methods.ipynb","provenance":[],"collapsed_sections":[]}},"cells":[{"cell_type":"markdown","metadata":{"id":"gq17tW1gz7UI","colab_type":"text"},"source":["# [Strings](https://docs.python.org/3/library/stdtypes.html#text-sequence-type-str)"]},{"cell_type":"markdown","metadata":{"id":"fsoI4U--z7UO","colab_type":"text"},"source":["***"]},{"cell_type":"markdown","metadata":{"id":"o3SXsO_Jz7UP","colab_type":"text"},"source":["# 1. Declaring a string.\n","

\n","\n","Strings should be enclosed in `' '` or `\" \"`\n","
\n","We cannot mix and match, i.e `\" '` or `' \"`\n","\n","

"]},{"cell_type":"markdown","metadata":{"id":"ff8NSVKuz7UQ","colab_type":"text"},"source":["### The right way.\n","

\n","Here we declare the same string with either method, and each gets stored to a seperate variable.\n","

"]},{"cell_type":"markdown","metadata":{"id":"EasWANavz7UR","colab_type":"text"},"source":["```python \n","good_string = 'Python is my favorite programming language!'\n","also_good = \"Python is my favorite programming language!\"\n","```"]},{"cell_type":"code","metadata":{"id":"Vfekkm0uz7US","colab_type":"code","colab":{}},"source":["good_string = 'Python is my favorite programming language!'\n","also_good = \"Python is my favorite programming language!\""],"execution_count":0,"outputs":[]},{"cell_type":"markdown","metadata":{"id":"cQwb6OFLz7UY","colab_type":"text"},"source":["
\n","
"]},{"cell_type":"markdown","metadata":{"id":"8HdOL65az7UZ","colab_type":"text"},"source":["### The wrong way.\n","

\n","\n","Notice the mismatch: `'...\"`\n","\n","

"]},{"cell_type":"markdown","metadata":{"collapsed":true,"id":"xtMpKm_lz7Ux","colab_type":"text"},"source":["```python\n","bad_string = 'Happy\"\n","```"]},{"cell_type":"code","metadata":{"id":"595qX1C-z7U1","colab_type":"code","colab":{}},"source":["bad_string = 'Happy\"'"],"execution_count":0,"outputs":[]},{"cell_type":"markdown","metadata":{"id":"kfnXUwZyz7U9","colab_type":"text"},"source":["
\n","
"]},{"cell_type":"markdown","metadata":{"id":"t2uB06xMz7U_","colab_type":"text"},"source":["### Built-in functions also work on strings."]},{"cell_type":"markdown","metadata":{"id":"i-n0PPcAz7VA","colab_type":"text"},"source":["```python\n","type(good_string)\n","```"]},{"cell_type":"code","metadata":{"id":"vPz6SoR0z7VB","colab_type":"code","outputId":"42a790e0-3dd7-4fbf-8a59-a1b9503e8cb9","colab":{}},"source":["type(good_string)"],"execution_count":0,"outputs":[{"output_type":"execute_result","data":{"text/plain":["str"]},"metadata":{"tags":[]},"execution_count":4}]},{"cell_type":"markdown","metadata":{"id":"zsq5WPyPz7VF","colab_type":"text"},"source":["
\n","
"]},{"cell_type":"markdown","metadata":{"id":"Z-TB3-oiz7VG","colab_type":"text"},"source":["### Length of a string: `len()`\n","

\n","\n","Here is a new built-in func. \n","
\n","`len()` returns the amount of characters in a string of text, *including* whitespace.\n","\n","

"]},{"cell_type":"markdown","metadata":{"id":"Cj0-FiQqz7VJ","colab_type":"text"},"source":["```python\n","len(good_string)\n","```"]},{"cell_type":"code","metadata":{"id":"4xuPWjtkz7VM","colab_type":"code","outputId":"abf2edfd-da72-4d79-fe3d-5f11691b1e39","colab":{}},"source":["len(good_string)"],"execution_count":0,"outputs":[{"output_type":"execute_result","data":{"text/plain":["43"]},"metadata":{"tags":[]},"execution_count":8}]},{"cell_type":"markdown","metadata":{"id":"md5nE3tYz7VQ","colab_type":"text"},"source":["***\n","
\n","
\n","
"]},{"cell_type":"markdown","metadata":{"id":"I-KZwYbLz7VR","colab_type":"text"},"source":["# 2. String Indexing\n","

\n","\n","This visual aide shows how python `indexes` strings, you can reference the positions along the string in 2 ways:\n","* Forwards: Positive Indices\n","* Backwards: Negative Indices\n","\n","
\n","\n","In programming a string has a more technical definition, technically speaking **a string is an array of individual characters**. \n","\n","**Arrays** are used to store multiple values in one single variable.\n","\n","**Note:** An **array** can be used interchangably with the term **list**, although the term array is used in multiple programming languages where as the term list is specifically used in python.\n","\n","[Array Documentation](https://www.w3schools.com/python/python_arrays.asp)\n","\n","

"]},{"cell_type":"markdown","metadata":{"id":"AcnKrLrnz7VS","colab_type":"text"},"source":["

"]},{"cell_type":"markdown","metadata":{"id":"Crsn-H1Oz7VT","colab_type":"text"},"source":["
\n","
"]},{"cell_type":"markdown","metadata":{"id":"pF_5Jwz6z7VU","colab_type":"text"},"source":["### Indexing"]},{"cell_type":"markdown","metadata":{"id":"tTVqbGSyz7VV","colab_type":"text"},"source":["

\n","\n","We use bracket notation to index a string\n","\n","```python \n","full_greeting = \"Hello Sam!\"\n","full_greeting[0]\n","```\n","We grab an individual character by referencing its position inside the brackets. Look at the image above to see how these positions break down along the string.\n","\n","

"]},{"cell_type":"code","metadata":{"id":"ro1iop6zz7VW","colab_type":"code","outputId":"f9a8d2c9-d644-4454-c759-b422fd4cf3eb","colab":{}},"source":["full_greeting = \"Hello Sam!\"\n","full_greeting[0]"],"execution_count":0,"outputs":[{"output_type":"execute_result","data":{"text/plain":["'H'"]},"metadata":{"tags":[]},"execution_count":9}]},{"cell_type":"markdown","metadata":{"id":"NEUVViInz7VZ","colab_type":"text"},"source":["
\n","
"]},{"cell_type":"markdown","metadata":{"id":"5KNSZWQ6z7Vd","colab_type":"text"},"source":["### Slicing"]},{"cell_type":"markdown","metadata":{"id":"bZFssEMRz7Vf","colab_type":"text"},"source":["

\n","\n","We use bracket notation to index a portion of the string as well, except we use a colon (`:`) to seperate the `start` and `stop` positions.\n","\n","```python\n","full_greeting = \"Hello Sam!\"\n","hello_string = full_greeting[0:5]\n","print(hello_string)\n","```\n","\n","We grab a string of characters by referencing the start and stop positions in the following way `string[start,stop]`. \n","\n","**Important note:** \n","- `start` index is *inclusive* \n","- `stop` index is *exclusive*\n","\n","

"]},{"cell_type":"code","metadata":{"id":"mPP2_0L6z7Vg","colab_type":"code","outputId":"7277c7a1-a417-42bd-e562-a899428c66e1","executionInfo":{"status":"ok","timestamp":1577408240633,"user_tz":480,"elapsed":334,"user":{"displayName":"Matt Hess","photoUrl":"","userId":"00800340733434721825"}},"colab":{"base_uri":"https://localhost:8080/","height":34}},"source":["full_greeting = \"Hello Sam!\"\n","hello_string = full_greeting[0:5]\n","print(hello_string)"],"execution_count":0,"outputs":[{"output_type":"stream","text":["Hello\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"_7IU_cNW2fRO","colab_type":"text"},"source":["#### Create the `hello_string` using negative indexes while slicing"]},{"cell_type":"code","metadata":{"id":"IfMMZlwE2lb7","colab_type":"code","outputId":"f9c40d91-a0fe-4860-856e-e89cf516ab51","executionInfo":{"status":"ok","timestamp":1577408367152,"user_tz":480,"elapsed":365,"user":{"displayName":"Matt Hess","photoUrl":"","userId":"00800340733434721825"}},"colab":{"base_uri":"https://localhost:8080/","height":34}},"source":["hello_string = full_greeting[-10: -5]\n","print(hello_string)"],"execution_count":0,"outputs":[{"output_type":"stream","text":["Hello\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"Yi_C3-M-z7Vj","colab_type":"text"},"source":["

\n","
\n","
\n","
"]},{"cell_type":"markdown","metadata":{"id":"qQfoE9d6z7Vk","colab_type":"text"},"source":["# 3. String Operations\n","

\n","\n","We can add strings together with `+` to craft sentences\n","\n","

"]},{"cell_type":"markdown","metadata":{"id":"rtbu0BMsz7Vl","colab_type":"text"},"source":["### Simple Example\n","

\n","\n","```python\n","greeting = \"Hello\"\n","name = \"Student\"\n","\n","print(greeting + name)\n","\n","# print() statement gives us a space for free when we use commas to seperate values!\n","print(greeting, name)\n","```\n","\n","

"]},{"cell_type":"code","metadata":{"id":"6L6EODbIz7Vm","colab_type":"code","outputId":"783a2492-0ca3-46de-9b7d-53359c62cf34","executionInfo":{"status":"ok","timestamp":1577408446096,"user_tz":480,"elapsed":392,"user":{"displayName":"Matt Hess","photoUrl":"","userId":"00800340733434721825"}},"colab":{"base_uri":"https://localhost:8080/","height":51}},"source":["greeting = \"Hello\"\n","name = \"Student\"\n","\n","print(greeting + name)\n","\n","# print() statement gives us a space for free when we use commas to seperate values!\n","print(greeting, name)"],"execution_count":0,"outputs":[{"output_type":"stream","text":["HelloStudent\n","Hello Student\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"qdszVOIKz7Vq","colab_type":"text"},"source":["### Complex Example\n","\n","

\n","\n","```python\n","greeting = \"Hello\"\n","name = \"Change me to your name!\"\n","\n","full_greeting = greeting + \" \" + name + \", how is everything?\n","print(full_greeting)\n","```\n","\n","

"]},{"cell_type":"code","metadata":{"id":"Wx9zGw1Mz7Vr","colab_type":"code","outputId":"c8963a0a-4c4e-44f5-9159-2ea1a7f6262e","executionInfo":{"status":"ok","timestamp":1577408486660,"user_tz":480,"elapsed":351,"user":{"displayName":"Matt Hess","photoUrl":"","userId":"00800340733434721825"}},"colab":{"base_uri":"https://localhost:8080/","height":34}},"source":["greeting = \"Hello\"\n","name = \"Change me to your name!\"\n","\n","full_greeting = greeting + \" \" + name + \", how is everything?\"\n","print(full_greeting)\n"],"execution_count":0,"outputs":[{"output_type":"stream","text":["Hello Change me to your name!, how is everything?\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"3aFsL6FBz7Vw","colab_type":"text"},"source":["

\n","
\n","
"]},{"cell_type":"markdown","metadata":{"id":"wnMkocWVz7Vy","colab_type":"text"},"source":["# 4. Strings and Logic\n","We can use the special python operator `in` to check if a string contains a particular `char`"]},{"cell_type":"markdown","metadata":{"id":"czmv9Q35z7Vy","colab_type":"text"},"source":["### `in` in action."]},{"cell_type":"markdown","metadata":{"id":"EfCHGLOEz7Vz","colab_type":"text"},"source":["```python\n","test = 'd' in 'dog'\n","print('is \"d\" in \"dog\"?', test)\n","```"]},{"cell_type":"code","metadata":{"id":"gwxjKE_Az7V0","colab_type":"code","outputId":"ee6498d8-491e-4ebe-f196-77b4ddbf6a9a","colab":{}},"source":["test = 'd' in 'dog'\n","print('is \"d\" in \"dog\"?', test)"],"execution_count":0,"outputs":[{"output_type":"stream","text":["is \"d\" in \"dog\"? True\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"HTJ-71Iaz7V2","colab_type":"text"},"source":["

\n","
\n","

-----------Strings Exercise (1)-------------

\n","
\n","

\n","
"]},{"cell_type":"markdown","metadata":{"id":"evvtTjoPz7V4","colab_type":"text"},"source":["# 5. Useful String Methods."]},{"cell_type":"markdown","metadata":{"id":"_Mta7AXuz7V7","colab_type":"text"},"source":["### A. `str.replace`"]},{"cell_type":"markdown","metadata":{"id":"zR_ZkIi7z7V9","colab_type":"text"},"source":["

\n","\n","If you don't know how something works, you can always check the **`help()`** function:\n","```python\n","help(str.replace)\n","```\n","\n","

"]},{"cell_type":"code","metadata":{"id":"pr6fCzrlz7WB","colab_type":"code","outputId":"4c1e4bcd-d34d-4cf9-9b19-2bdfeec4f2e9","colab":{}},"source":["help(str.replace)"],"execution_count":0,"outputs":[{"output_type":"stream","text":["Help on method_descriptor:\n","\n","replace(...)\n"," S.replace(old, new[, count]) -> str\n"," \n"," Return a copy of S with all occurrences of substring\n"," old replaced by new. If the optional argument count is\n"," given, only the first count occurrences are replaced.\n","\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"PMEqFXs6z7WE","colab_type":"text"},"source":["
"]},{"cell_type":"markdown","metadata":{"id":"irymxTPYz7WE","colab_type":"text"},"source":["#### What does `str.replace` do?"]},{"cell_type":"markdown","metadata":{"id":"Db-QtaBxz7WH","colab_type":"text"},"source":["```python\n","good_string = 'Python is my favorite programming language!'\n","good_string.replace('a', '?')\n","```"]},{"cell_type":"code","metadata":{"id":"ry43VAoxz7WH","colab_type":"code","outputId":"75cf68f1-a162-42b1-d210-1e0ce50cfb6f","colab":{}},"source":["good_string = 'Python is my favorite programming language!'\n","good_string.replace('a', '?')"],"execution_count":0,"outputs":[{"output_type":"execute_result","data":{"text/plain":["'Python is my f?vorite progr?mming l?ngu?ge!'"]},"metadata":{"tags":[]},"execution_count":29}]},{"cell_type":"markdown","metadata":{"id":"Ev4zUCEKz7WL","colab_type":"text"},"source":["
"]},{"cell_type":"markdown","metadata":{"id":"k-obq6Iiz7WM","colab_type":"text"},"source":["#### `.replace` will NOT modify `good_string` in place.\n","Meaning in order for us to see the changes we will need to re-assign a variable with the return value of the `replace` method, unless we reference the mutation itself, return of the method, in print statement.\n","

\n","\n","\n","

\n","\n","```python\n","good_string = 'Python is my favorite programming language!'\n","print(\"Before .replace():\", good_string)\n","\n","good_string.replace('a', '?')\n","print(\"After .replace():\", good_string)\n","```\n","\n","

"]},{"cell_type":"code","metadata":{"id":"9_Wpz57-z7WN","colab_type":"code","outputId":"6898a8a4-3615-4443-a4ae-556fddb5af23","colab":{}},"source":["good_string = 'Python is my favorite programming language!'\n","print(\"Before .replace():\", good_string)\n","\n","good_string.replace('a', '?')\n","print(\"After .replace():\", good_string)\n"],"execution_count":0,"outputs":[{"output_type":"stream","text":["Before .replace(): Python is my favorite programming language!\n","After .replace(): Python is my favorite programming language!\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"6RWbCVp8z7WR","colab_type":"text"},"source":["
"]},{"cell_type":"markdown","metadata":{"id":"AosMwajrz7WS","colab_type":"text"},"source":["#### Store the return value of `.replace` instead."]},{"cell_type":"markdown","metadata":{"collapsed":true,"id":"VWh00NCLz7WS","colab_type":"text"},"source":["

\n","\n","```python\n","good_string = 'Python is my favorite programming language!'\n","print(\"Before replace():\", good_string)\n","\n","good_string = good_string.replace('is', 'will be')\n","print(\" After replace() AND store:\", good_string)\n","```\n","\n","

"]},{"cell_type":"code","metadata":{"id":"dUjoi9F7z7WT","colab_type":"code","outputId":"ac95f59f-ed8b-4540-e30a-4252d4699288","executionInfo":{"status":"ok","timestamp":1577410380521,"user_tz":480,"elapsed":345,"user":{"displayName":"Matt Hess","photoUrl":"","userId":"00800340733434721825"}},"colab":{"base_uri":"https://localhost:8080/","height":51}},"source":["good_string = 'Python is my favorite programming language!'\n","print(\"Before replace():\", good_string)\n","\n","good_string = good_string.replace('is', 'will be')\n","print(\" After replace() AND store:\", good_string)"],"execution_count":0,"outputs":[{"output_type":"stream","text":["Before replace(): Python is my favorite programming language!\n"," After replace() AND store: Python will be my favorite programming language!\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"uCNnFae5z7WV","colab_type":"text"},"source":["
\n","
"]},{"cell_type":"markdown","metadata":{"id":"uPv41K8Lz7WW","colab_type":"text"},"source":["### B. `str.split()`\n","\n","This method will return a `list` data type"]},{"cell_type":"markdown","metadata":{"collapsed":true,"id":"MKIey8jDz7WX","colab_type":"text"},"source":["#### Splitting on `White-Space`\n","\n","

\n","\n","```python\n","sentence = 'three different words'\n","words = sentence.split()\n","\n","print(words)\n","print(type(words))\n","```\n","\n","

"]},{"cell_type":"code","metadata":{"id":"gF1QSGEJz7WX","colab_type":"code","outputId":"e2dd1251-628c-4917-88c1-041ca2464476","colab":{}},"source":["sentence = 'three different words'\n","words = sentence.split()\n","\n","print(words)\n","print(type(words))\n"],"execution_count":0,"outputs":[{"output_type":"stream","text":["['three', 'different', 'words']\n","\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"rxQK7zjgz7Wb","colab_type":"text"},"source":["
"]},{"cell_type":"markdown","metadata":{"collapsed":true,"id":"0Ti4s7aBz7We","colab_type":"text"},"source":["#### Splitting on a `Comma` `,`\n","

\n","\n","```python\n","secret_binary_data = '01001,101101,11100000'\n","binaries = secret_binary_data.split(',')\n","\n","print(binaries)\n","print(type(binaries))\n","```\n","\n","

"]},{"cell_type":"code","metadata":{"id":"TEON0MTAz7Wf","colab_type":"code","outputId":"275f9d04-895a-419b-9382-3ee0c800dae2","colab":{}},"source":["secret_binary_data = '01001,101101,11100000'\n","binaries = secret_binary_data.split(',')\n","\n","print(binaries)\n","print(type(binaries))"],"execution_count":0,"outputs":[{"output_type":"stream","text":["['01001', '101101', '11100000']\n","\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"-0YaGfHVz7Wj","colab_type":"text"},"source":["***\n","
\n","
\n","
"]},{"cell_type":"markdown","metadata":{"id":"e5MF-45Az7Wl","colab_type":"text"},"source":["# 6. \"Cleaning\" Strings\n","## More string methods"]},{"cell_type":"markdown","metadata":{"collapsed":true,"id":"rPx9zds1z7Wm","colab_type":"text"},"source":["```python\n","mixed_case = 'PyTHoN hackER'\n","```"]},{"cell_type":"code","metadata":{"id":"8R7Ipmcpz7Wm","colab_type":"code","colab":{}},"source":["mixed_case = 'PyTHoN hackER'"],"execution_count":0,"outputs":[]},{"cell_type":"markdown","metadata":{"id":"2C5akv2jz7Wo","colab_type":"text"},"source":["
"]},{"cell_type":"markdown","metadata":{"id":"musGXQ5Pz7Wp","colab_type":"text"},"source":["### C. `str.upper()`\n","\n","#### `upper-case` all leters in a string.\n","\n","This string method does not happen in place, meaning in order for us to see the changes we will need to re-assign a variable with the return value of the method, unless we reference the mutation itself, return of the method, in print statement.\n","

\n","\n","```python\n","mixed_case.upper()\n","print(mixed_case)\n","```\n","\n","

"]},{"cell_type":"markdown","metadata":{"id":"a-M2UVsIDKbj","colab_type":"text"},"source":["#### Run the code above... why is the change not working...?"]},{"cell_type":"code","metadata":{"id":"DCOy3t-3z7Wp","colab_type":"code","outputId":"7f52690f-d90d-4487-9fc1-77a65eceed52","colab":{}},"source":["print(mixed_case.upper())\n","print(mixed_case)"],"execution_count":0,"outputs":[{"output_type":"stream","text":["PYTHON HACKER\n","PyTHoN hackER\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"NBj0uF6Nz7Ws","colab_type":"text"},"source":["
"]},{"cell_type":"markdown","metadata":{"id":"WQEnsgDOz7Wu","colab_type":"text"},"source":["### D. `str.lower()`\n","\n","#### `lower-case` all letters in a string.\n","\n","This string method does not happen in place, meaning in order for us to see the changes we will need to re-assign a variable with the return value of the method, unless we reference the mutation itself, return of the method, in print statement.\n","\n","

\n","\n","```python\n","mixed_case.lower()\n","print(mixed_case)\n","```\n","\n","

"]},{"cell_type":"markdown","metadata":{"id":"2dwumYR5AT73","colab_type":"text"},"source":["#### Run the code above... why is the change not working...?\n","\n","Because we need to print the return of the string lower right away because this operation does not happen in place."]},{"cell_type":"code","metadata":{"id":"mdUK0DcYz7Wu","colab_type":"code","outputId":"1666a676-09de-4a83-f5d3-293e0374989f","colab":{}},"source":["print(mixed_case.lower())\n","print(mixed_case)"],"execution_count":0,"outputs":[{"output_type":"stream","text":["python hacker\n","PyTHoN hackER\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"o2GUcKJez7W0","colab_type":"text"},"source":["
"]},{"cell_type":"markdown","metadata":{"id":"xp9IUJJ_z7W1","colab_type":"text"},"source":["### E. `str.title()`\n","\n","#### `str.title` will captitalize each of the first letters of every word in a string and make all other characters in the string lowercase, like a book title.\n","\n","This string method does not happen in place, meaning in order for us to see the changes we will need to re-assign a variable with the return value of the method, unless we reference the mutation itself, return of the method, in print statement.\n","\n","\n","

\n","\n","```python\n","mixed_case.title()\n","print(mixed_case)\n","```\n","\n","

"]},{"cell_type":"markdown","metadata":{"id":"9C0Fc9FNAl2k","colab_type":"text"},"source":["#### Run the code above... why is the change not working...?"]},{"cell_type":"code","metadata":{"id":"eqfQOSeMz7W3","colab_type":"code","outputId":"280fafdb-7d2d-4ca3-fa5f-a2e62f2e3df0","colab":{}},"source":["print(mixed_case.title())\n","print(mixed_case)"],"execution_count":0,"outputs":[{"output_type":"stream","text":["Python Hacker\n","PyTHoN hackER\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"Hf-54bY9AqYj","colab_type":"text"},"source":["
"]},{"cell_type":"markdown","metadata":{"id":"gANNNQv-z7W8","colab_type":"text"},"source":["### F. `str.strip()`\n","\n","#### `str.strip()` removes BOTH `Leading` and `Trailing` whitespace.\n","\n","This string method does not happen in place, meaning in order for us to see the changes we will need to re-assign a variable with the return value of the method, unless we reference the mutation itself, return of the method, in print statement.\n","

\n","\n","```python\n","ugly_format = ' \\n \\t Some story to tell \\n'\n","print('ugly:', ugly_format)\n","print('stripped:', ugly_format.strip())\n","```\n","\n","

"]},{"cell_type":"markdown","metadata":{"id":"QrFPijrVA2M-","colab_type":"text"},"source":["#### Run the code above... Notice how the change worked, but only because we referenced the mutation itself in print()"]},{"cell_type":"code","metadata":{"id":"Skxx1f_pz7W8","colab_type":"code","outputId":"0e4baf5f-843b-4f5a-c6ad-bea1d783065f","executionInfo":{"status":"ok","timestamp":1577411094933,"user_tz":480,"elapsed":1124,"user":{"displayName":"Matt Hess","photoUrl":"","userId":"00800340733434721825"}},"colab":{"base_uri":"https://localhost:8080/","height":86}},"source":["ugly_format = ' \\n \\t Some story to tell \\n'\n","print('ugly:', ugly_format)\n","print('stripped:', ugly_format.strip())"],"execution_count":0,"outputs":[{"output_type":"stream","text":["ugly: \n"," \t Some story to tell \n","\n","stripped: Some story to tell\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"gApC4quMz7XA","colab_type":"text"},"source":["
"]},{"cell_type":"markdown","metadata":{"id":"HqvxLl9Gz7XB","colab_type":"text"},"source":["### These methods do NOT change the original string.\n","\n","#### In order to to use the mutated string, you MUST `save` to `new_variable` or `overwrite` the `original`.\n","

\n","\n","```python\n","lowered = mixed_case.lower()\n","print(\"original string:\", mixed_case)\n","print(\"lowered string:\", lowered)\n","```\n","\n","

"]},{"cell_type":"code","metadata":{"id":"2Gj6o4Kgz7XC","colab_type":"code","outputId":"7f2a3953-3f7c-4a47-908d-4319404589b5","colab":{}},"source":["lowered = mixed_case.lower()\n","print(\"original string:\", mixed_case)\n","print(\"lowered string:\", lowered)"],"execution_count":0,"outputs":[{"output_type":"stream","text":["original string: PyTHoN hackER\n","lowered string: python hacker\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"w_AW0vqZz7XE","colab_type":"text"},"source":["***\n","
\n","
\n","
"]},{"cell_type":"markdown","metadata":{"id":"B2q_Jpq9z7XF","colab_type":"text"},"source":["# 7. \"Chaining\" Methods"]},{"cell_type":"markdown","metadata":{"id":"ath2-2fGz7XG","colab_type":"text"},"source":["### method `chaining` in action.\n","

\n","\n","```python\n","ugly_mixed_case = ' ThIS LooKs BAd '\n","pretty = ugly_mixed_case.strip().lower().replace('bad', 'good')\n","print(pretty)\n","```\n","\n","

"]},{"cell_type":"code","metadata":{"id":"d_dDI4m3z7XI","colab_type":"code","outputId":"24cce0d2-d23e-433e-d965-dfc38d011ea9","colab":{}},"source":["ugly_mixed_case = ' ThIS LooKs BAd '\n","pretty = ugly_mixed_case.strip().lower().replace('bad', 'good')\n","print(pretty)"],"execution_count":0,"outputs":[{"output_type":"stream","text":["this looks good\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"TeOfKV5Dz7XL","colab_type":"text"},"source":["### Let's break it down."]},{"cell_type":"markdown","metadata":{"id":"ZdeFCvJoz7XP","colab_type":"text"},"source":["

\n","\n","```python\n","ugly_mixed_case = ' ThIS LooKs BAd '\n","print(ugly_mixed_case)\n","\n","pretty = ugly_mixed_case.strip()\n","print(pretty)\n","\n","prettier = ugly_mixed_case.strip().lower()\n","print(prettier)\n","\n","prettiest = ugly_mixed_case.strip().lower().replace('bad', 'good')\n","print(prettiest)\n","```\n","\n","

"]},{"cell_type":"code","metadata":{"id":"i61Ax_0_z7XQ","colab_type":"code","outputId":"ce9a18f0-3731-44c6-9780-cdc34d3466a5","colab":{}},"source":["ugly_mixed_case = ' ThIS LooKs BAd '\n","print(ugly_mixed_case)\n","\n","pretty = ugly_mixed_case.strip()\n","print(pretty)\n","\n","prettier = ugly_mixed_case.strip().lower()\n","print(prettier)\n","\n","prettiest = ugly_mixed_case.strip().lower().replace('bad', 'good')\n","print(prettiest)\n"],"execution_count":0,"outputs":[{"output_type":"stream","text":[" ThIS LooKs BAd \n","ThIS LooKs BAd\n","this looks bad\n","this looks good\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"jmKYqQazz7XT","colab_type":"text"},"source":["### Note that execution order is from `left` to `right`. Thus, *THIS* won't work the same:"]},{"cell_type":"markdown","metadata":{"collapsed":true,"id":"-OMW8pNMz7XU","colab_type":"text"},"source":["```python\n","ugly_mixed_case = ' ThIS LooKs BAd '\n","pretty = ugly_mixed_case.replace('bad', 'good').strip().lower()\n","print(pretty)\n","```"]},{"cell_type":"code","metadata":{"id":"PNkdChzzz7XV","colab_type":"code","outputId":"3b3bf80a-3bbd-48c3-c89f-2d602a5d4ab9","colab":{}},"source":["ugly_mixed_case = ' ThIS LooKs BAd '\n","pretty = ugly_mixed_case.replace('bad', 'good').strip().lower()\n","print(pretty)"],"execution_count":0,"outputs":[{"output_type":"stream","text":["this looks bad\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"H6zcp4FZz7XY","colab_type":"text"},"source":["***\n","
\n","
\n","
"]},{"cell_type":"markdown","metadata":{"id":"eds5qL_4z7XY","colab_type":"text"},"source":["## Bonus: [Escape characters](http://python-reference.readthedocs.io/en/latest/docs/str/escapes.html#escape-characters)"]},{"cell_type":"markdown","metadata":{"collapsed":true,"id":"JJWsZ-iXz7XZ","colab_type":"text"},"source":["### `newline` : `\\n`\n","

\n","\n","```python\n","two_lines = 'First line\\nSecond line'\n","print(two_lines)\n","```\n","\n","

"]},{"cell_type":"code","metadata":{"id":"a7rocuxPz7Xa","colab_type":"code","outputId":"e11991f1-daa7-4554-d73e-2b147f610418","colab":{}},"source":["two_lines = 'First line\\nSecond line'\n","print(two_lines)\n","two_lines.split(\"\\n\")"],"execution_count":0,"outputs":[{"output_type":"stream","text":["First line\n","Second line\n"],"name":"stdout"},{"output_type":"execute_result","data":{"text/plain":["['First line', 'Second line']"]},"metadata":{"tags":[]},"execution_count":48}]},{"cell_type":"markdown","metadata":{"id":"ep-UrVwWz7Xe","colab_type":"text"},"source":["
"]},{"cell_type":"markdown","metadata":{"collapsed":true,"id":"g0RapiaAz7Xe","colab_type":"text"},"source":["### `indent` : `\\t`\n","

\n","\n","```python\n","indented = '\\tThis will be indented'\n","print(indented)\n","```\n","\n","

"]},{"cell_type":"code","metadata":{"id":"NQubvZP-z7Xe","colab_type":"code","outputId":"0693d4f6-ebfc-4bb0-80db-f86fca720a88","colab":{}},"source":["indented = '\\tThis will\\t be indented'\n","print(indented)\n","indented.split(\"\\t\")"],"execution_count":0,"outputs":[{"output_type":"stream","text":["\tThis will\t be indented\n"],"name":"stdout"},{"output_type":"execute_result","data":{"text/plain":["['', 'This will', ' be indented']"]},"metadata":{"tags":[]},"execution_count":50}]},{"cell_type":"markdown","metadata":{"collapsed":true,"id":"yZkVWxKkz7Xh","colab_type":"text"},"source":["

\n","
\n","

-----------String Exercises (2)(3)-------------

\n","
\n","

\n","
"]}]}

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