In [1]:
nums = [1, 2, 3, 4, 5]
s = sum(x * x for x in nums)
print(s)
In [2]:
# Determine if any .py files exist in a directory
import os
files = os.listdir(os.path.expanduser('~'))
if any(name.endswith('.py') for name in files):
print('There be python!')
else:
print('Sorry, no python.')
# Output a tuple as CSV
s = ('ACME', 50, 123.45)
print(','.join(str(x) for x in s))
# Data reduction across fields of a data structure
portfolio = [
{'name':'GOOG', 'shares': 50},
{'name':'YHOO', 'shares': 75},
{'name':'AOL', 'shares': 20},
{'name':'SCOX', 'shares': 65}
]
min_shares = min(s['shares'] for s in portfolio)
print(min_shares)
min()
and max()
accept a key argument that might be useful in situations where you might be inclined to use a generator.
In [3]:
# Original: Returns 20
min_shares = min(s['shares'] for s in portfolio)
print(min_shares)
# Alternative: Returns {'name': 'AOL', 'shares': 20}
min_shares = min(portfolio, key=lambda s: s['shares'])
print(min_shares)