Python cheatsheet

python_cheatsheet.txt

# List comprehension
list = []
result = [expr(item) for item in list if item < 5]

# Dict comprehension
dict = dict()
dict = {key: value for key in list}

# Range
x = range(2, 5)
x = [2, 3, 4]

# Split/Join
list = string.split()
" ".join(list)


# For loops
for n in numbers:
  print(n)
  
for header, rows in zip(headers, rows):
  print("{}: {}".format(header, ", ".join(rows)))
  
 for num, line in enumerate(lines):
   print("{0:03d}: {1}".format(num, line))
   
   
# Counting
l = ["a", "b", "b"]
[ [x, l.count(x)] for x in set(l) ] # gives list of list
dict((x, l.count(x)) for x in set(l)) # gives dict

from collections import Counter
Counter(l) -> Counter({'b': 2, 'a': 1})