CODEWITHSUNDEEP
pythonpython-3.x
eedarb
eedarb

Reputation: 21

Concatenating strings from multiple lines in a file separated by newlines

If I have a file with multiple lines like: 

name1  
12345  
67890

name2  
23456  
78901

name3  
34567  
89012

How would I go about concatenating each line in the form:

"name1 1234567890"

"name2 2345678901"

"name3 3456789012"

Specifically, what is the best way to concatenate strings from a file into a single line until an empty line is encountered?

Upvotes: 2

Views: 2277

Answers (4)

John La Rooy
John La Rooy

Reputation: 304137

Here's a way that doesn't read the entire file into memory at once. I also don't assume that there are only 3 lines in each group.

>>> from itertools import groupby
>>> with open("fin") as fin:
...     groups = groupby(fin, str.isspace)
...     for name, *rest in (map(str.strip, v) for  g,v in groups if not g):
...         print(name, " ", *rest, sep="")
... 
name1 1234567890
name2 2345678901
name3 3456789012

Upvotes: 0

Pedro Lobito
Pedro Lobito

Reputation: 98881

It can be done with just split. 

for x in open('the_file', 'r').read().split('\n\n'): # split the file on empty lines
    m = x.split() # split on line break
    print '"{} {}{}"\n'.format(m[0], m[1], m[2])

Output:

"name1 1234567890"

"name2 2345678901"

"name3 3456789012"

Upvotes: 0

Chiheb Nexus
Chiheb Nexus

Reputation: 9257

Assuming your input file is called file_input and your output file is called file_output, you can do something like this:

# Read your input file, removing \n and spliting by spaces
with open("input_file", 'r') as f:
    data = f.read().rstrip().split()

# Opening a new file in append mode 'a' 
with open("output_file", 'a') as f:
    # Processing your data by iterating through the data list with steps
    n = ['"{0} {1}"'.format(k, "".join(v)) for k,*v in zip(data[::3], data[1::3], data[2::3])]
    for k in n:
        f.write(k+"\n")

Output:

"name1 1234567890"
"name2 2345678901"
"name3 3456789012"

Upvotes: 0

Zohaib Ijaz
Zohaib Ijaz

Reputation: 22885

You can split first with \n\n and then split \n to get each item. 

data = open('file_name').read()

output = ["%s %s%s" % tuple(item.split('\n')) for item in data.split('\n\n')]

['name1 1234567890', 'name2 2345678901', 'name3 3456789012']

Upvotes: 1

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