練習(xí)代碼

print("Let's practice everything.")
print('You\'d need to know \'bout escapes with \\ that do:')
print('\n newlines and \t tabs.')

poem = """
\tThe lovely world
with logic so firmly planted
cannot discern \n the needs of love
nor comprehend passion from intuition
and requires an explanation
\n\t\twhere there is none.
"""

print("--------------")
print(poem)
print("--------------")

five = 10 - 2 + 3 - 6
print(f"This should be five: {five}")

def secret_formula(started):
    jelly_beans = started * 500
    jars = jelly_beans / 1000
    crates = jars / 100
    # return a tuple
    return jelly_beans, jars, crates

start_point = 10000
# print(type(secret_formula(start_point)))
# unpack the tuple
beans, jars, crates = secret_formula(start_point)

# remember that this is another way to format a string
print("With a starting point of : {}".format(start_point))
# it's just like with an f""string
print(f"We'd have {beans} beans, {jars} jars, and {crates} crates.")

start_point = start_point / 10
print("We can also do that this way:")
formula = secret_formula(start_point)
# this is an easy way to apply a list to a format string
print("We'd have {} beans, {} jars, and {} crates.".format(*formula))

Study Drills

1. Make sure to do your checks: read it backward, read it out loud, and put comments above confusing parts.

2. Break the file on purpose, then run it to see what kinds of errors you get. Make sure you can fix it.

補(bǔ)充

1.  # this is an easy way to apply a list to a format string
    print("We'd have {} beans, {} jars, and {} crates.".format(*formula))
   

   這里作者說“這是一個(gè)便于將list中的值賦給格式化字符串的方法。”，但確切地說，函數(shù)secret_formula返回的是一個(gè)元組(tuple)，而*formula也是一種unpack操作。