title: PyYAML error: "yaml.scanner.ScannerError: mapping values are not allowed here"
body: <p>I'm getting a strange error when parsing a YAML:</p>
  
  <pre><code>yaml.scanner.ScannerError: mapping values are not allowed here
  </code></pre>
  
  <p>The YAML file I'm trying to read is valid according to <a href="http://www.yamllint.com/" rel="nofollow noreferrer">YAML Lint</a></p>
  
  <p>Another strange thing is that it works fine on my laptop (Arch Linux) but not on the Server (Ubuntu). The PyYAML version is the same though on both machines.</p>
  
  <p>I have seen  <a href="https://stackoverflow.com/questions/9055371/python-and-pyaml-yaml-scanner-scannererror-mapping-values-are-not-allowed-her">the other posts on stackoverflow where people were missing the space after the colon</a>, but I'm not missing any spaces.</p>
  
  <p>This is the complete YAML file:</p>
  
  <pre class="lang-yaml prettyprint-override"><code>pipeline:
      - read:
              input: /home/omnibrain/projects/company/data/data.csv
              output: some_data
      - filter:
              input: some_data
              filtername: latlng_filter
              minlat: 32.5
              maxlat: 32.9
              minlng: -117.4
              maxlng: -117.0
      - enhance:
              input: some_data
              enhancername: geo_enhancer
              fields: zip
      - write:
              input: some_data
              writername: csv_writer
              output_dir: /home/omnibrain/outputs
              columns: [id, latitude, longitude, zip, networktype]
              filename: example1 # the output filename
  </code></pre>
  
  <p>And this is the complete stack trace:</p>
  
  <pre><code>Traceback (most recent call last):
    File "/usr/local/bin/someproject", line 9, in &lt;module&gt;
      load_entry_point('someproject==0.0.1', 'console_scripts', 'someproject')()
    File "/usr/local/lib/python3.4/dist-packages/someproject-0.0.1-py3.4.egg/someproject/__init__.py", line 19, in main
      pipeline.Pipeline(parser.parse_args().scriptfile).start()
    File "/usr/local/lib/python3.4/dist-packages/someproject-0.0.1-py3.4.egg/someproject/pipeline/pipeline.py", line 20, in __init__
      self._raw_pipeline = self._parse_yaml(yamlscript)
    File "/usr/local/lib/python3.4/dist-packages/someproject-0.0.1-py3.4.egg/someproject/pipeline/pipeline.py", line 55, in _parse_yaml
      data = yaml.load(yamlscript)
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/__init__.py", line 72, in load
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/constructor.py", line 35, in get_single_data
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 36, in get_single_node
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 55, in compose_document
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 84, in compose_node
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 133, in compose_mapping_node
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 82, in compose_node
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 111, in compose_sequence_node
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 84, in compose_node
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 133, in compose_mapping_node
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 84, in compose_node
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 127, in compose_mapping_node
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/parser.py", line 98, in check_event
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/parser.py", line 428, in parse_block_mapping_key
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/scanner.py", line 116, in check_token
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/scanner.py", line 220, in fetch_more_tokens
    File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/scanner.py", line 580, in fetch_value
  yaml.scanner.ScannerError: mapping values are not allowed here
    in "./test1.yaml", line 3, column 93
  </code></pre>