Lecture 6

class: title-slide, left, bottom

# Lecture 6
----
## **DANL 100: Programming for Data Analytics**
### Byeong-Hak Choe
### September 15, 2022

---
# Announcement

### <p style="color:#00449E">Accounting Expo</p>

- Are you interested in learning about Accounting, Consulting, Audit or Tax?
  - Stop in for pizza and meet 20+ Firms (alumni and employers) from the Big 4, National Players and Regional firms!

- When? September 15th, 5:00 PM-7:00 PM

- Where? Ballroom

- Dress code? Business Casual

---
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# Workflow
<html><div style='float:left'></div><hr color='#EB811B' size=1px width=796px></html>

---
# Workflow
### <p style="color:#00449E"> Shortcuts </p>
- **F9** runs a current line (where the blinking cursor bar is) or selected lines.

- **Home/End** moves the blinking cursor bar to the beginning/end of the line.
  - **Fn + ** <svg aria-hidden="true" role="img" viewBox="0 0 448 512" style="height:1em;width:0.88em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M447.1 256C447.1 273.7 433.7 288 416 288H109.3l105.4 105.4c12.5 12.5 12.5 32.75 0 45.25C208.4 444.9 200.2 448 192 448s-16.38-3.125-22.62-9.375l-160-160c-12.5-12.5-12.5-32.75 0-45.25l160-160c12.5-12.5 32.75-12.5 45.25 0s12.5 32.75 0 45.25L109.3 224H416C433.7 224 447.1 238.3 447.1 256z"/></svg> / <svg aria-hidden="true" role="img" viewBox="0 0 448 512" style="height:1em;width:0.88em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M438.6 278.6l-160 160C272.4 444.9 264.2 448 256 448s-16.38-3.125-22.62-9.375c-12.5-12.5-12.5-32.75 0-45.25L338.8 288H32C14.33 288 .0016 273.7 .0016 256S14.33 224 32 224h306.8l-105.4-105.4c-12.5-12.5-12.5-32.75 0-45.25s32.75-12.5 45.25 0l160 160C451.1 245.9 451.1 266.1 438.6 278.6z"/></svg> works too.

- **PgUp/PgDn** moves the blinking cursor bar to the top/bottom line of the script on the screen. 
  - **Fn + ** <svg aria-hidden="true" role="img" viewBox="0 0 384 512" style="height:1em;width:0.75em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M374.6 246.6C368.4 252.9 360.2 256 352 256s-16.38-3.125-22.62-9.375L224 141.3V448c0 17.69-14.33 31.1-31.1 31.1S160 465.7 160 448V141.3L54.63 246.6c-12.5 12.5-32.75 12.5-45.25 0s-12.5-32.75 0-45.25l160-160c12.5-12.5 32.75-12.5 45.25 0l160 160C387.1 213.9 387.1 234.1 374.6 246.6z"/></svg> / <svg aria-hidden="true" role="img" viewBox="0 0 384 512" style="height:1em;width:0.75em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M374.6 310.6l-160 160C208.4 476.9 200.2 480 192 480s-16.38-3.125-22.62-9.375l-160-160c-12.5-12.5-12.5-32.75 0-45.25s32.75-12.5 45.25 0L160 370.8V64c0-17.69 14.33-31.1 31.1-31.1S224 46.31 224 64v306.8l105.4-105.4c12.5-12.5 32.75-12.5 45.25 0S387.1 298.1 374.6 310.6z"/></svg> works too.

---
# Workflow
### <p style="color:#00449E"> Shortcuts </p>

.pull-left[
### <p style="color:#00449E"> Mac </p>
- **command + N** opens a new script.
- **command + 1** is the shortcut for #.
- **command + 4** is the shortcut for block comment.
]

.pull-right[
### <p style="color:#00449E"> Windows </p>
- **Ctrl + N** opens a new script.
- **Ctrl + 1** is the shortcut for #.
- **Ctrl + 4** is the shortcut for block comment.
]

---
# Workflow
### <p style="color:#00449E"> More Shortcuts </p>

- **Ctrl** (**command** for Mac Users) **+ Z** undoes the previous action.
- **Ctrl** (**command** for Mac Users) **+ Shift + Z** redoes when undo is executed.

- **Ctrl** (**command** for Mac Users) **+ F** is useful when finding a phrase in the script.
- **Ctrl** (**command** for Mac Users) **+ R** is useful when replacing a specific phrase with something in the script.

- **Ctrl** (**command** for Mac Users) **+ D** deletes a current line.

---
# Workflow
### <p style="color:#00449E"> Code and comment style </p>
- The two main principles for coding and managing data are:
  - Make things easier for your future self.
  - Don't trust your future self.

- The `#` mark is Spyder's comment character.
  - The `#` character has many names: `hash`, `sharp`, `pound`, or `octothorpe`.
  - `#` indicates that the rest of the line is to be ignored.
  - Write comments before the line that you want the comment to apply to.

- Consider using block commenting for separating code sections.
  - `# %%` defines a coding block in Spyder.

---
class: inverse, center, middle

# Numbers
<html><div style='float:left'></div><hr color='#EB811B' size=1px width=796px></html>

---
# Numbers

- Let's look at the following Python’s simplest built-in data types in detail:

- **Booleans** (which have the value `True` or `False`)
  
  - **Integers** (whole numbers such as `10` and `28`)
  
  - **Floats** (numbers with decimal points such as `3.141592`, or sometimes exponents like `1.0e8`, which means one times ten to the eighth power, or `100000000.0`)

---
# Numbers
### <p style="color:#00449E"> Integer Operations </p>

.pull-left[
- Python can be a simple calculator.

- Here is a table of the math operators:

]
.pull-right[
- Dividing by zero with either kind of division causes a Python exception

```python
12 + 8
12 - 8
13 * 1.2
2 + 3 * 4
2 ** 3
2 / 0
2 // 0
```
]

---
# Numbers
### <p style="color:#00449E"> Integers and Variables </p>

- We can combine the arithmetic operators with assignment by putting the operator before the `=`.

.pull-left[

```python
a = 72
a -= 2   # This is like a = a - 2
```

]

.pull-right[

```python
b = 62
b += 2    # This is like b = b + 2
```
]

.pull-left[

```python
c = 72
c *= 2   # This is like c = c * 2
```

]

.pull-right[

```python
d = 62
d /= 2    # This is like d = d / 2
```

]

---
# Numbers
### <p style="color:#00449E"> Type Conversions </p>

- To change other Python data types to an integer, use the `int()` function.
  - `int()` keeps the whole number and discard any fractional part.

- `True` and `False` are converted to integer values `1` and `0`.

.pull-left[

```python
int(True)
int(False)
```

]

.pull-right[

```python
bool(1)
bool(0)
```
]

.pull-left[

```python
int(72.3)
int(1.0e4)
```

]

.pull-right[

```python
bool(1.0)
bool(0.0)
```

]

---
# Numbers
### <p style="color:#00449E"> Floats </p>

- To convert other types to floats, we use the `float()` function.

.pull-left[

```python
float(True)
float(False)
```

]

.pull-right[

```python
float(88)
float('89')
```
]

---
# Workflow
### <p style="color:#00449E"> Continue Lines with `\` </p>

.panelset[

.panel[.panel-name[With `\`]

```python
sum = 1 + \
      2 + \
      3 + \
      4
sum
```
]

.panel[.panel-name[Without `\`]

```python
sum = 1 + 
```
]

.panel[.panel-name[With `()`]
- If you’re in the middle of paired parentheses (or square or curly brackets), Python doesn’t squawk about line endings:

```python
sum = ( 1 +  
        2 +  
        3 +
        4 )
sum
```
]

]

---
# Numbers
### <p style="color:#00449E"> Class Exercises </p>
1. Multiply the number of seconds in a minute (`60`) by the number of minutes in an hour (also `60`) using Python.

2. Assign the result from the previous task (seconds in an hour) to a variable called `seconds_per_hour`.

3. How many seconds are in a day? Use your `seconds_per_hour` variable.

4. Calculate seconds per day again, but this time save the result in a variable called `seconds_per_day`

5. Divide `seconds_per_day` by `seconds_per_hour`. Use floating-point (`/`) division.

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# Choose with `if`
<html><div style='float:left'></div><hr color='#EB811B' size=1px width=796px></html>