Built-in Names¶

View Built-ins¶

1. List All¶

# Access built-in namespace
print(dir(__builtins__))

# Count
print(len(dir(__builtins__)))

2. Check Built-in¶

import builtins

print(hasattr(builtins, 'list'))    # True
print(hasattr(builtins, 'myvar'))   # False

Don't Shadow¶

1. Type Constructors¶

# Don't shadow these!
# int = 42        
# float = 3.14    
# str = "text"    
# list = []       
# dict = {}       
# tuple = ()      
# set = set()     
# bool = True

2. Common Functions¶

# Don't shadow
# len = 5       # Very bad!
# range = []    
# print = "x"   # Very bad!
# input = 42    
# sum = 0       # Common mistake!
# max = 10      # Common mistake!
# min = 1       # Common mistake!

3. Iteration¶

# Don't shadow
# iter = []     
# next = 1      
# filter = []   
# map = {}      
# sorted = []   # Very common!
# reversed = []

Recovery¶

1. Delete Shadow¶

# Shadowed
list = [1, 2, 3]

# Recover
del list
list(range(5))  # Works

2. Access builtins¶

import builtins

# Even if shadowed
len = 42
builtins.len([1, 2, 3])  # Works

Safe Alternatives¶

Don't Use	Use Instead
`sum`	`total`
`list`	`items`, `data_list`
`dict`	`mapping`
`type`	`kind`, `data_type`
`id`	`identifier`
`max`	`maximum`
`min`	`minimum`
`sorted`	`ordered`