DSC 20 Lecture 5

Dictionary iterates keys by default

d = {"key1":"value1","key2":"value2","key3":"value3"}  
for key in d:  
	print(key)  

Basic File Usage

with open(file_name, [access_mode]) as f:

• file_name: a string value
• access_mode: determines the mode in which the file has to be opened, i.e., read, write, append, etc.

f methods

• f.write(data): writes the string to the file, needs '\n' if writing multiple lines

access modes

• w: overwrites the file
• a: appends data to the end of the file
• r: read-only file access

Ways to read a file

with open('myfile.txt', 'r') as f:

1. print(f.read())
2. for line in f.readlines():\n\tprint(line)
3. for line in f:\n\tprint(line)