ch_1_practice.txt

## 1. Which of the following are operators, and which are values?

Operators: *  -  /  +
Values: 'hello'  -88.8  5


## 2. Which of the following is a variable, and which is a string?
spam is a variable
'spam' is a string


## 3. Name three data types.
int, float, string


## 4. What is an expression made up of? What do all expressions do?
An expression is made up of operator(s) and argument(s).
All expressions evaluate to a single value.


## 5. This chapter introduced assignment statements, like spam = 10.
##What is the difference between an expression and a statement?

An assignment statement results in a value being assigned to a variable.
An expression is stand-alone and doesn't get assigned to a variable.

An expression evaluates to a single value. A statement does not.


## 6. What does the variable bacon contain after the following code runs?
bacon = 20
bacon + 1

bacon contains 20


## 7. What should the following two expressions evaluate to?
'spam' + 'spamspam'
'spam' * 3

Both evaluate to 'spamspamspam'


## 8. Why is eggs a valid variable name while 100 is invalid?
Variable names can't start with a number. There would be no way for
Python to tell the variable 100 apart from the number 100.


## 9. What three functions can be used to get the integer, floating-point number,
## or string version of a value?

int(), float(), str()


## 10. Why does this expression cause an error? How can you fix it?
'I have eaten ' + 99 + ' burritos.'

## Python can't concatenate a string and a number. Using str() on the 99
## can fix it:
'I have eaten ' + str(99) + ' burritos.'
    

## Extra credit: Search online for the Python documentation for the len()
## function. It will be on a web page titled “Built-in Functions.” Skim the
## list of other functions Python has, look up what the round() function does,
## and experiment with it in the interactive shell.

len(s)
Return the length (the number of items) of an object. The argument may be a
sequence (such as a string, bytes, tuple, list, or range) or a collection
(such as a dictionary, set, or frozen set).

round(number[, ndigits])
Return the floating point value number rounded to ndigits digits after the
decimal point. If ndigits is omitted, it returns the nearest integer to
its input. Delegates to number.__round__(ndigits).