python open filemode code example

Example 1: python file open modes

r for reading
r+ opens for reading and writing (cannot truncate a file)
w for writing
w+ for writing and reading (can truncate a file)
rb for reading a binary file. The file pointer is placed at the beginning of the file.
rb+ reading or writing a binary file
wb+ writing a binary file
a+ opens for appending
ab+ Opens a file for both appending and reading in binary. The file pointer is at the end of the file if the file exists. The file opens in the append mode.
x open for exclusive creation, failing if the file already exists (Python 3)

Example 2: read file python

document = 'document.txt'
file = open(document, 'r')
# 'r' can be replaced with:
# 'w' to write
# 'a' to append (add to the end)
# 'w+' makes a new file if one does not already exist of that name
# 'a+' is the same as 'w+' but it appends if the file does exist

##go to beginning of document
file.seek(0)

##print all lines in document, except empty lines:
for i in file:
    k = i.strip() 
    print k

##close the file after you are done
file.close()


##this can temporarily open a file:
with open(document) as ur:
    for i in ur:
        k = i.strip() 
        print k

Example 3: read and write to file python

file = open(“testfile.txt”, “r+”)