36

I am trying to find all the occurences of "|" in a string.

def findSectionOffsets(text):
    startingPos = 0
    endPos = len(text)

    for position in text.find("|",startingPos, endPos):
        print position
        endPos = position

But I get an error:

    for position in text.find("|",startingPos, endPos):
TypeError: 'int' object is not iterable
theAlse
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    `text.find("|",startingPos, endPos)` is giving you a single `int` value, which the for loop is iterating on... – avasal Oct 22 '12 at 10:40
  • http://stackoverflow.com/questions/4664850/find-all-occurrences-of-a-substring-in-python – georg Oct 22 '12 at 10:57

7 Answers7

63

The function: 

def findOccurrences(s, ch):
    return [i for i, letter in enumerate(s) if letter == ch]


findOccurrences(yourString, '|')

will return a list of the indices of yourString in which the | occur.

Mooncrater
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Marco L.
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  • how does that loop work? `i for i, letter in enumerate(s) if letter == ch`. – Goodword Jun 22 '15 at 23:04
  • @Goodword:This answer uses a *list comprehension*; see the [Python tutorial](https://docs.python.org/2/tutorial/datastructures.html#list-comprehensions). – Martijn Pieters Jun 01 '16 at 23:43
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    The function is spelled wrong on the definition line. It should be "def findOccurrences" with two r's. – R. Wayne Feb 04 '18 at 00:20
13

if you want index of all occurrences of | character in a string you can do this

import re
str = "aaaaaa|bbbbbb|ccccc|dddd"
indexes = [x.start() for x in re.finditer('\|', str)]
print(indexes) # <-- [6, 13, 19]

also you can do

indexes = [x for x, v in enumerate(str) if v == '|']
print(indexes) # <-- [6, 13, 19]
Hussein Esmail
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avasal
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2

It is easier to use regular expressions here;

import re

def findSectionOffsets(text):
    for m in re.finditer('\|', text):
        print m.start(0)
Roland Smith
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2
import re
def findSectionOffsets(text)
    for i,m in enumerate(re.finditer('\|',text)) :
        print i, m.start(), m.end()
dbr
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Zulu
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1

text.find returns an integer (the index at which the desired string is found), so you can run for loop over it.

I suggest:

def findSectionOffsets(text):
    indexes = []
    startposition = 0

    while True:
        i = text.find("|", startposition)
        if i == -1: break
        indexes.append(i)
        startposition = i + 1

    return indexes
M.Shuaib Imran
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samfrances
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1

text.find() only returns the first result, and then you need to set the new starting position based on that. So like this:

def findSectionOffsets(text):
    startingPos = 0

    position = text.find("|", startingPos):
    while position > -1:
        print position
        startingPos = position + 1
        position = text.find("|", startingPos)
M Somerville
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1

If text is the string that you want to count how many "|" it contains, the following line of code returns the count:

len(text.split("|"))-1

Note: This will also work for searching sub-strings.

Pablo Reyes
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